List of ancient architectural records

The list of ancient architectural records consists of record-making architectural achievements of the Greco-Roman world

Classical antiquity

Classical antiquity is a broad term for a long period of cultural history centered on the Mediterranean Sea, comprising the interlocking civilizations of ancient Greece and ancient Rome, collectively known as the Greco-Roman world...

from ca. 800 BC to 600 AD.

Bridges

The highest bridge over the water or ground was the single-arched Pont d'Aël
Pont d'Aël
The Pont d'Aël is a Roman aqueduct bridge in the village of the same name, in the comune of Aymavilles, in Aosta Valley, Italy. The bridge, constructed in 3 BC, carried water for the agricultural lands of the newly founded colony Augusta Prætoria Salassorum across a side valley, 66 m...

which carried irrigation water for Aosta
Aosta
Aosta is the principal city of the bilingual Aosta Valley in the Italian Alps, north-northwest of Turin. It is situated near the Italian entrance of the Mont Blanc Tunnel, at the confluence of the Buthier and the Dora Baltea, and at the junction of the Great and Little St. Bernard routes...

across a deep Alpine gorge. The height of its deck over the torrent below measures 66 m.

The largest bridge by span was the Trajan's Bridge
Trajan's bridge
Trajan's Bridge or Bridge of Apollodorus over the Danube was a Roman segmental arch bridge, the first to be built over the lower Danube. For more than a thousand years, it was the longest arch bridge in the world, in terms of both total and span length...

over the lower Danube. Its twenty-one timber arches spanned 50 m each from centreline to centreline.

The largest pointed arch bridge by span was the Karamagara Bridge
Karamagara Bridge
The Karamagara Bridge is a late Roman bridge in the ancient region of Cappadocia in eastern Turkey, and possibly the earliest known pointed arch bridge.- Location and situation:...

in Cappadocia
Cappadocia
Cappadocia is a historical region in Central Anatolia, largely in Nevşehir Province.In the time of Herodotus, the Cappadocians were reported as occupying the whole region from Mount Taurus to the vicinity of the Euxine...

with a clear span of 17 m. Constructed in the 5th or 6th century AD across a tributary of the Euphrates, the now submerged structure is one if the earliest known examples of pointed architecture in late antiquity
Late Antiquity
Late Antiquity is a periodization used by historians to describe the time of transition from Classical Antiquity to the Middle Ages, in both mainland Europe and the Mediterranean world. Precise boundaries for the period are a matter of debate, but noted historian of the period Peter Brown proposed...

, and may even be the oldest surviving pointed arch bridge.

The largest rivers to be spanned by solid bridges were the Danube
Danube
The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....

and the Rhine, the two largest European rivers west of the Eurasian Steppe
Eurasian Steppe
The Eurasian Steppe is the vast steppe ecoregion of Eurasia in the Temperate grasslands, savannas, and shrublands Biome. It stretches from Hungary to Mongolia...

. The lower Danube was crossed at least at two different crossing points (at Drobeta-Turnu Severin
Trajan's bridge
Trajan's Bridge or Bridge of Apollodorus over the Danube was a Roman segmental arch bridge, the first to be built over the lower Danube. For more than a thousand years, it was the longest arch bridge in the world, in terms of both total and span length...

and at Corabia) and the middle and lower Rhine at four (at Mainz, at Neuwied
Caesar's Rhine bridges
Caesar's Bridge across the Rhine, the first two bridges to cross the Rhine River, were built by Julius Caesar and his legionaries during the Gallic War in 55 BC and 53 BC, respectively...

, at Koblenz and at Cologne). For rivers with strong currents and to allow swift army movements, pontoon bridges were also routinely employed. Going from the distinct lack of records of solid bridges spanning larger rivers elsewhere, the Roman feat appears to be unsurpassed anywhere in the world until well into the 19th century.

The longest bridge, and one of the longest of all time, was Constantine's Bridge with an overall length of 2,437 m, 1137 m of which crossed the Danube's riverbed. Pont Serme
Pont Serme
The Pont Serme or Pons Selinus, later called the Pons Septimus, was a Roman bridge of the Via Domitia in Hérault, southern France. The approximately 1500 m long viaduct crossed the wide marshes of the Orb River and the Etang de Capestang west of Béziers, surpassing in terms of length even the...

in southern France reached a length of 1,500 m, but may be better classified as an arcaded viaduct
Viaduct
A viaduct is a bridge composed of several small spans. The term viaduct is derived from the Latin via for road and ducere to lead something. However, the Ancient Romans did not use that term per se; it is a modern derivation from an analogy with aqueduct. Like the Roman aqueducts, many early...

. The second longest bridge was thus the acclaimed Trajan's Bridge
Trajan's bridge
Trajan's Bridge or Bridge of Apollodorus over the Danube was a Roman segmental arch bridge, the first to be built over the lower Danube. For more than a thousand years, it was the longest arch bridge in the world, in terms of both total and span length...

further upstream from Constantine's. Erected 104–105 AD by the engineer Apollodorus of Damascus
Apollodorus of Damascus
Apollodorus of Damascus was a Greek engineer, architect, designer and sculptor who flourished during the 2nd century AD, from Damascus, Roman Syria. He was a favourite of Trajan, for whom he constructed Trajan's Bridge over the Danube for the 105-106 campaign in Dacia. He also designed the Forum...

for facilitating the advance of Roman troops in the Dacian Wars, it featured twenty-one spans covering a total distance of between 1,070 and 1,100 m. The longest existing Roman bridge is the sixty-two span Puente Romano
Puente Romano (Mérida)
The Puente Romano is a Roman bridge over the Guadiana River at Mérida, Spain. It is the longest surviving bridge from ancient times, having once featured an estimated overall length of 755 m with 62 spans. Today, there are 60 spans on a length of 721 m between the abutments...

at Mérida, Spain
Mérida, Spain
Mérida is the capital of the autonomous community of Extremadura, western central Spain. It has a population of 57,127 . The Archaeological Ensemble of Mérida is a UNESCO World Heritage site since 1993.- Climate :...

(today 790 m). The total length of all aqueduct
Aqueduct
An aqueduct is a water supply or navigable channel constructed to convey water. In modern engineering, the term is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose....

arch bridges of the Aqua Marcia
Aqua Marcia
The Aqua Marcia was the longest of the 11 aqueducts that supplied the city of ancient Rome. The still-functioning Acqua Felice from 1586 runs on long stretches along the route of the Aqua Marcia....

to Rome
Rome
Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...

, constructed from 144 to 140 BC, amounts to 10 km.

The longest segmental arch bridge was the ca. 1,100 m long Trajan's Bridge
Trajan's bridge
Trajan's Bridge or Bridge of Apollodorus over the Danube was a Roman segmental arch bridge, the first to be built over the lower Danube. For more than a thousand years, it was the longest arch bridge in the world, in terms of both total and span length...

, whose wooden superstructure was supported by twenty concrete piers. The Bridge at Limyra
Limyra Bridge
The Limyra Bridge is a late Roman bridge in Lycia, in modern south-west Turkey, and one of the oldest segmented arch bridges in the world. The long bridge is located near the ancient city of Limyra, and spans the Alakır Çayı river over 26 segmental arches...

in modern-day Turkey, consisting of twenty-six flat brick arches, features the greatest lengths of all extant masonry structures in this category (360 m).

The tallest bridge was the Pont du Gard
Pont du Gard
The Pont du Gard is a notable ancient Roman aqueduct bridge that crosses the Gard River in southern France. It is part of a long aqueduct that runs between Uzès and Nîmes in the South of France. It is located in Vers-Pont-du-Gard near Remoulins, in the Gard département...

, which carried water across the Gard river
Gardon
The Gardon or Gard is a river in southern France. It is the namesake of the Gard département. Several of its tributaries are also called Gardon....

to Nîmes
Nîmes
Nîmes is the capital of the Gard department in the Languedoc-Roussillon region in southern France. Nîmes has a rich history, dating back to the Roman Empire, and is a popular tourist destination.-History:...

, southern France. The 270 m long aqueduct
Aqueduct
An aqueduct is a water supply or navigable channel constructed to convey water. In modern engineering, the term is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose....

bridge was constructed in three tiers which measure successively 20.5 m, 19.5 m and 7.4 m, adding up to a total height of 47.4 m above the water-level. When crossing deeper valleys, Roman hydraulic engineers preferred inverted siphons over bridges for reasons of relative economics; this is evident in the Gier aqueduct where seven out of nine siphons exceed the 45 m mark, reaching depths up to 123 m. The tallest road bridges were the monumental Alcántara Bridge
Alcántara Bridge
The Alcántara Bridge is a Roman stone arch bridge built over the Tagus River at Alcántara, Spain between 104 and 106 CE by an order of the Roman Emperor Trajan in 98...

, Spain (ca. 42 m), and the bridge at Narni
Narni
Narni is an ancient hilltown and comune of Umbria, in central Italy, with 20,100 inhabitants, according to the 2003 census. At an altitude of 240 m , it overhangs a narrow gorge of the Nera River in the province of Terni. It is very close to the Geographic center of Italy...

(30 m).

The widest bridge was the Pergamon Bridge
Pergamon Bridge
The Pergamon Bridge is a Roman substruction bridge over the Selinus river in the ancient city of Pergamon , modern-day Turkey...

in Pergamon
Pergamon
Pergamon , or Pergamum, was an ancient Greek city in modern-day Turkey, in Mysia, today located from the Aegean Sea on a promontory on the north side of the river Caicus , that became the capital of the Kingdom of Pergamon during the Hellenistic period, under the Attalid dynasty, 281–133 BC...

, Turkey. The structure served as a substruction for a large court in front of the Serapis
Serapis
Serapis or Sarapis is a Graeco-Egyptian name of God. Serapis was devised during the 3rd century BC on the orders of Ptolemy I of Egypt as a means to unify the Greeks and Egyptians in his realm. The god was depicted as Greek in appearance, but with Egyptian trappings, and combined iconography...

Temple, allowing the waters of the Selinus river to pass unrestricted underneath. Measuring 193 m in width, the dimensions of the extant bridge are such that it is frequently mistaken for a tunnel, although the whole structure was actually erected above ground. A similar design was also executed in the Nysa Bridge
Nysa Bridge
The Nysa Bridge is a late imperial Roman bridge over the Cakircak stream in Nysa , in the ancient region of Caria, Turkey. The long substructure was the second largest of its kind in antiquity, after the Pergamon Bridge.- Dating :...

which straddled the local stream on a length of 100 m, supporting a forecourt of the city theatre
Roman theatre (structure)
The characteristics of Roman to those of the earlier Greek theatres due in large part to its influence on the Roman triumvir Gnaeus Pompeius Magnus. Much of the architectural influence on the Romans came from the Greeks, and theatre structural design was no different from other buildings...

. By comparison, the width of a normal, free standing Roman bridge did not exceed 10 m.

The bridge with the greatest load capacity – as far as can be determined from the limited research – was the Alcántara Bridge
Alcántara Bridge
The Alcántara Bridge is a Roman stone arch bridge built over the Tagus River at Alcántara, Spain between 104 and 106 CE by an order of the Roman Emperor Trajan in 98...

the largest arch of which can support a load of 52 t, followed by the Ponte de Pedra (30 t), Puente Bibei (24 t) and Puente de Ponte do Lima (24 t) (all in Hispania
Hispania
Another theory holds that the name derives from Ezpanna, the Basque word for "border" or "edge", thus meaning the farthest area or place. Isidore of Sevilla considered Hispania derived from Hispalis....

). According to modern calculations, the Limyra Bridge
Limyra Bridge
The Limyra Bridge is a late Roman bridge in Lycia, in modern south-west Turkey, and one of the oldest segmented arch bridges in the world. The long bridge is located near the ancient city of Limyra, and spans the Alakır Çayı river over 26 segmental arches...

, Asia Minor
Asia Minor
Asia Minor is a geographical location at the westernmost protrusion of Asia, also called Anatolia, and corresponds to the western two thirds of the Asian part of Turkey...

, can support a 30 t vehicle on one arch plus a load of 500 kp/m²
Kilogram-force
A kilogram-force , or kilopond , is a gravitational metric unit of force. It is equal to the magnitude of the force exerted by one kilogram of mass in a gravitational field...

on the remaining surface of the arch. The load limit of Roman arch bridges was thus far in excess of the live loads imposed by ancient traffic.

Ratio of clear span against rise, arch rib and pier thickness:

The bridge with the flattest arches was the Trajan's Bridge
Trajan's bridge
Trajan's Bridge or Bridge of Apollodorus over the Danube was a Roman segmental arch bridge, the first to be built over the lower Danube. For more than a thousand years, it was the longest arch bridge in the world, in terms of both total and span length...

, with a span-to-rise ratio of about 7 to 1. It also held several other important architectural records (see below). A number of fully stone segmental arch bridges, scattered throughout the empire
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....

, featured ratios of between 6.4 and 3, such as the relatively unknown Bridge at Limyra
Limyra Bridge
The Limyra Bridge is a late Roman bridge in Lycia, in modern south-west Turkey, and one of the oldest segmented arch bridges in the world. The long bridge is located near the ancient city of Limyra, and spans the Alakır Çayı river over 26 segmental arches...

, the Ponte San Lorenzo
Ponte San Lorenzo
The Ponte San Lorenzo is a Roman segmental arch bridge over the river Bacchiglione in Padua, Italy. Constructed between 47 and 30 BC, it is one of the very earliest segmental arched bridges in the world...

and the Alconétar Bridge
Alconétar Bridge
The Alconétar Bridge , also known as Puente de Mantible, was a Roman segmental arch bridge in the Extremadura region, Spain. The ancient structure, which featured flattened arches with a span-to-rise ratio of 4–5:1, is one of the earliest of its kind...

. By comparison, the Florentine Ponte Vecchio
Ponte Vecchio
The Ponte Vecchio is a Medieval stone closed-spandrel segmental arch bridge over the Arno River, in Florence, Italy, noted for still having shops built along it, as was once common. Butchers initially occupied the shops; the present tenants are jewellers, art dealers and souvenir sellers...

, one of the earliest segmental arch bridges in the Middle Ages
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

, features a ratio of 5.3 to 1.

The bridge with the most slender arch was the Pont-Saint-Martin
Pont-Saint-Martin Bridge
The Pont-Saint-Martin is a Roman segmental arch bridge in the Aosta Valley in Italy dating to the 1st century BC.The span is according to recent research, but frequently stated to be 35.64 m or 36.65 m....

in the Alpine Aosta Valley. A favourable ratio of arch rib thickness to span is regarded as the single most important parameter in the design of stone arches. The arch rib of the Pont-Saint-Martin is only 1.03 m thick what translates to a ratio of 1/34 respectively 1/30 depending on whether one assumes 35.64 m or 31.4 m to be the value for its clear span. A statistical analysis of extant Roman bridges shows that ancient bridge builders preferred a ratio for rib thickness to span of 1/10 for smaller bridges, while they reduced this to as low as 1/20 for larger spans in order to relieve the arch from its own weight.

The bridge with the most slender piers was the three-span Ponte San Lorenzo
Ponte San Lorenzo
The Ponte San Lorenzo is a Roman segmental arch bridge over the river Bacchiglione in Padua, Italy. Constructed between 47 and 30 BC, it is one of the very earliest segmental arched bridges in the world...

in Padua
Padua
Padua is a city and comune in the Veneto, northern Italy. It is the capital of the province of Padua and the economic and communications hub of the area. Padua's population is 212,500 . The city is sometimes included, with Venice and Treviso, in the Padua-Treviso-Venice Metropolitan Area, having...

, Italy. A favourable ratio between pier thickness and span is considered a particularly important parameter in bridge building, since wide openings reduce stream velocities which tend to undermine the foundations and cause collapse. The approximately 1.70 m thick piers of the Ponte San Lorenzo are as slender as one-eighth of the span. In some Roman bridges, the ratio still reached one-fifth, but a common pier thickness was around one third of the span. Having been completed sometime between 47 and 30 BC, the San Lorenzo Bridge also represents one of the earliest segmental arch bridges in the world with a span to rise ratio of 3.7 to 1.

Canals

The largest canal appears to be the Ancient Suez Canal connecting the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...

and the Red Sea
Red Sea
The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...

via the Nile
Nile
The Nile is a major north-flowing river in North Africa, generally regarded as the longest river in the world. It is long. It runs through the ten countries of Sudan, South Sudan, Burundi, Rwanda, Democratic Republic of the Congo, Tanzania, Kenya, Ethiopia, Uganda and Egypt.The Nile has two major...

. Opened by king Ptolemy II around 280 BC the waterway branched off the Pelusiac arm of the river running eastwards through the Wadi Tumalat to the Bitter Lakes on a length of 55.6 km. There, it turned sharply south following the modern course of the canal and discharged into the Red Sea after altogether 92.6 km. The canal was 10 m deep and 35 m wide, with its sea entrance secured by a lock
Lock (water transport)
A lock is a device for raising and lowering boats between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is...

. Under Trajan
Trajan
Trajan , was Roman Emperor from 98 to 117 AD. Born into a non-patrician family in the province of Hispania Baetica, in Spain Trajan rose to prominence during the reign of emperor Domitian. Serving as a legatus legionis in Hispania Tarraconensis, in Spain, in 89 Trajan supported the emperor against...

the Ptolemaic
Ptolemaic Kingdom
The Ptolemaic Kingdom in and around Egypt began following Alexander the Great's conquest in 332 BC and ended with the death of Cleopatra VII and the Roman conquest in 30 BC. It was founded when Ptolemy I Soter declared himself Pharaoh of Egypt, creating a powerful Hellenistic state stretching from...

canal was restored and extended for about another 60 km to the south where it now tapped the main branch of the Nile at Babylon
Babylon (Egypt)
Babylon , was a fortress city or castle in the Delta of Egypt...

. A particularly ambitious canal scheme which never came to fruition was Nero
Nero
Nero , was Roman Emperor from 54 to 68, and the last in the Julio-Claudian dynasty. Nero was adopted by his great-uncle Claudius to become his heir and successor, and succeeded to the throne in 54 following Claudius' death....

's Corinth Canal
Corinth Canal
The Corinth Canal is a canal that connects the Gulf of Corinth with the Saronic Gulf in the Aegean Sea. It cuts through the narrow Isthmus of Corinth and separates the Peloponnesian peninsula from the Greek mainland, thus effectively making the former an island. The builders dug the canal through...

project, work on which was abandoned after his murder.

Columns

Note: This section makes no difference between columns composed of drums and monolithic shafts; for records concerning solely the latter, see monoliths.

The tallest Corinthian columns, a style which was particularly popular in Roman monumental construction, adorned the Temple of Jupiter at Baalbek
Baalbek
Baalbek is a town in the Beqaa Valley of Lebanon, altitude , situated east of the Litani River. It is famous for its exquisitely detailed yet monumentally scaled temple ruins of the Roman period, when Baalbek, then known as Heliopolis, was one of the largest sanctuaries in the Empire...

, reaching a height of 19.82 m including base and capital
Capital (architecture)
In architecture the capital forms the topmost member of a column . It mediates between the column and the load thrusting down upon it, broadening the area of the column's supporting surface...

; their shafts measure 16.64 m high. The next two tallest are those of the Temple of Mars Ultor in Rome and of the Athenian Olympieion which are 17.74 m (14.76 m) respectively 16.83 m (14 m) high. These are followed by a group of three virtually identical high Corinthian orders in Rome: the Hadrianeum
Temple of Hadrian
The Temple of Hadrian is a temple to the deified Hadrian on the Campus Martius in Rome, Italy, built by his adoptive son and successor Antoninus Pius in 145 and now incorporated into a later building in the Piazza di Pietra...

, the Temple of Apollo Sosianus
Temple of Apollo Sosianus
The Temple of Apollo Sosianus is a Roman temple dedicated to Apollo in the Campus Martius, next to the Theatre of Marcellus and the Porticus Octaviae, in Rome, Italy...

and the Temple of Castor and Pollux
Temple of Castor and Pollux
The Temple of Castor and Pollux is an ancient edifice in the Roman Forum, Rome, central Italy. It was originally built in gratitude for victory at the Battle of Lake Regillus . Castor and Pollux were the Dioscuri, the "twins" of Gemini, the twin sons of Zeus and Leda...

, all of which are in the order of 14.8 m (12.4 m) height. All these colonnade
Colonnade
In classical architecture, a colonnade denotes a long sequence of columns joined by their entablature, often free-standing, or part of a building....

s, though, are eclipsed by the single Pompey's Pillar
Pompey's Pillar (column)
Pompey's Pillar is a Roman triumphal column in Alexandria, Egypt, and the largest of its type constructed outside of the imperial capitals of Rome and Constantinople...

which is 26.85 m high with its base and capital (20.46 m without).

The tallest victory column
Victory column
A victory column is a monument in the form of a column, erected in memory of a victorious war or battle. The column stands on a base and is crowned with a victory symbol in the form of a statue...

was the Column of Marcus Aurelius
Column of Marcus Aurelius
The Column of Marcus Aurelius is a Roman victory column in Piazza Colonna, Rome, Italy. It is a Doric column featuring a spiral relief: it was built in honour of Roman emperor Marcus Aurelius and modeled on Trajan's Column.- Construction :...

, Rome, with the height of its top above ground being ca. 39.72 m. It thus exceeds its model, Trajan's Column
Trajan's Column
Trajan's Column is a Roman triumphal column in Rome, Italy, which commemorates Roman emperor Trajan's victory in the Dacian Wars. It was probably constructed under the supervision of the architect Apollodorus of Damascus at the order of the Roman Senate. It is located in Trajan's Forum, built near...

, by 4.65 m, chiefly due to its higher pedestal
Pedestal
Pedestal is a term generally applied to the support of a statue or a vase....

. In antiquity, the imperial capitals of Rome and Constantinople
Constantinople
Constantinople was the capital of the Roman, Eastern Roman, Byzantine, Latin, and Ottoman Empires. Throughout most of the Middle Ages, Constantinople was Europe's largest and wealthiest city.-Names:...

saw the erection of many more triumphal columns, some of which, like the demolished Column of Justinian
Column of Justinian
The Column of Justinian was a Roman triumphal column erected in Constantinople by the Byzantine emperor Justinian I in honour of his victories in 543...

, may well have exceeded these heights.

Dams

The largest arch dam
Arch dam
An arch dam is a type of dam that is curved and commonly built with concrete. The arch dam is a structure that is designed to curve upstream so that the force of the water against it, known as hydrostatic pressure, presses against the arch, compressing and strengthening the structure as it pushes...

was the Glanum Dam
Glanum Dam
The Glanum Dam, also known as the Vallon de Baume dam, was a Roman arch dam built to supply water to the Roman town of Glanum, the remains of which stand outside the town of Saint-Rémy-de-Provence in south-west France. It was situated south of Glanum, in a gorge that cut into the hills of Les...

in the French Provence
Provence
Provence ; Provençal: Provença in classical norm or Prouvènço in Mistralian norm) is a region of south eastern France on the Mediterranean adjacent to Italy. It is part of the administrative région of Provence-Alpes-Côte d'Azur...

. Since its remains were almost completey obliterated by a 19th century dam on the same spot, its reconstruction relies on prior documentation, according to which the Roman dam was 12 m high, 3.9 m wide and 18 m long at the crest. Being the earliest known arch dam, it remained unique in antiquity and beyond (aside from the Dara Dam
Dara Dam
The Dara Dam was a Roman arch dam at Dara in Mesopotamia , a rare pre-modern example of this dam type. The modern identification of its site is uncertain, but may rather point to a common gravity dam.- Ancient account :...

whose dimensions are unknown).

The largest arch-gravity dam
Arch-gravity dam
An arch-gravity dam, curved-gravity dam or arched dam is a dam with the characteristics of both an arch dam and a gravity dam. It is a dam that curves upstream in a narrowing curve that directs most of the water against the canyon rock walls, providing the force to compress the dam...

was the Kasserine Dam
Kasserine Dam
The Kasserine Dam was a Roman dam at Kasserine , Tunisia. The curved structure which dates to the 2nd century AD is variously classified as arch-gravity dam or gravity dam....

in Tunisia
Tunisia
Tunisia , officially the Tunisian RepublicThe long name of Tunisia in other languages used in the country is: , is the northernmost country in Africa. It is a Maghreb country and is bordered by Algeria to the west, Libya to the southeast, and the Mediterranean Sea to the north and east. Its area...

, arguably the biggest Roman dam in North Africa with 150 m length by 10 m height by 7.3 m width. However, despite its curved nature, it is uncertain whether the 2nd century AD dam structurally acted by arching action and not solely by its sheer weight; in this case it would be classified as a gravity dam and considerably smaller structures in Turkey or the Spanish Puy Foradado Dam
Puy Foradado Dam
The Puy Foradado Dam was a Roman arch-gravity dam in Zaragoza province, Aragon, Spain, dating to the 2nd or 3rd century AD.- See also :* List of Roman dams and reservoirs* Roman architecture* Roman engineering...

would move up in this category (see sortable List of Roman dams).

The largest bridge dam was the Band-e Kaisar which was erected by a Roman workforce on Sassanid territory in the 3rd century AD. The approximately 500 m long structure, a novel combination of overflow dam
Weir
A weir is a small overflow dam used to alter the flow characteristics of a river or stream. In most cases weirs take the form of a barrier across the river that causes water to pool behind the structure , but allows water to flow over the top...

and arcaded bridge
Arch bridge
An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side...

, crossed Iran's most effluent river on more than forty arches. The most eastern Roman civil engineering structure ever built, its dual-purpose design exerted a profound influence on Iranian dam building.

The largest multiple arch buttress dam was the Esparragalejo Dam
Esparragalejo Dam
The Esparragalejo Dam was a Roman multiple arch buttress dam at Esparragalejo, Badajoz province, Extremadura, Spain. Dating to the 1st century AD, it is the earliest known dam of its kind....

in Spain, whose 320 m long wall was supported on its air face alternatingly by buttresses and concave-shaped arches. Dated to the 1st century AD, the structure represents the first and, as it appears, only known dam of its type in ancient times.

The longest buttress dam
Buttress dam
A buttress dam or hollow dam is a dam with a solid, water-tight upstream side that is supported at intervals on the downstream side by a series of buttresses or supports. The dam wall may be flat or curved. Most buttress dams are made of reinforced concrete and are heavy, pushing the dam into the...

was the 632+ m long Consuegra Dam
Consuegra Dam
The Consuegra Dam was a Roman buttress dam in Toledo province, Castilla-La Mancha, Spain, dating to the 3rd or 4th century AD.- See also :* List of Roman dams and reservoirs* Roman architecture* Roman engineering...

(3rd–4th century AD) in central Spain which is still fairly well preserved. Instead of an earth embankment, its only 1.3 m thick retaining wall was supported on the downstream side by buttresses in regular intervals of 5 to 10 m. In Spain, a large number of ancient buttress dams are concentrated, representing nearly one-third of the total found there.

The longest gravity dam, and longest dam overall, impounds the Lake of Homs in Syria. Built in 284 AD by emperor Diocletian
Diocletian
Diocletian |latinized]] upon his accession to Diocletian . c. 22 December 244 – 3 December 311), was a Roman Emperor from 284 to 305....

for irrigation, the 2,000 m long and 7 m high masonry dam consists of a concrete core protected by basalt ashlar. The lake, 6 miles long by 2.5 miles wide, had a capacity of 90 million m³, making it the biggest Roman reservoir in the Near East and possibly the largest artificial lake constructed up to that time. Enlarged in the 1930s, it is still a landmark of Homs
Homs
Homs , previously known as Emesa , is a city in western Syria and the capital of the Homs Governorate. It is above sea level and is located north of Damascus...

which it continues to supply with water. Further notable dams in this category include the little-studied 900 m long Wadi Caam II dam at Leptis Magna
Leptis Magna
Leptis Magna also known as Lectis Magna , also called Lpqy, Neapolis, Lebida or Lebda to modern-day residents of Libya, was a prominent city of the Roman Empire. Its ruins are located in Khoms, Libya, east of Tripoli, on the coast where the Wadi Lebda meets the sea...

and the Spanish dams at Alcantarilla
Alcantarilla Dam
The Alcantarilla Dam was a Roman gravity dam in Toledo province, Castilla-La Mancha, Spain, dating to the 1st century AD.- See also :* List of Roman dams and reservoirs* Roman architecture* Roman engineering...

and at Consuegra
Consuegra Dam
The Consuegra Dam was a Roman buttress dam in Toledo province, Castilla-La Mancha, Spain, dating to the 3rd or 4th century AD.- See also :* List of Roman dams and reservoirs* Roman architecture* Roman engineering...

.

The tallest dam belonged to the Subiaco Dams
Subiaco Dams
The Subiaco Dams were a group of three Roman gravity dams at Subiaco, Lazio, Italy, devised as pleasure lakes for emperor Nero . The biggest one was the highest dam in the Roman Empire, and even in the world until its destruction in 1305.- See also :...

at the central Italian town of the same name
Subiaco, Italy
Subiaco is a town and comune in the Province of Rome, in Lazio, Italy, from Tivoli alongside the river Aniene. It is mainly renowned as a tourist and religious resort for its sacred grotto , in the St. Benedict's Abbey, and the other Abbey of St. Scholastica...

. Constructed by Nero
Nero
Nero , was Roman Emperor from 54 to 68, and the last in the Julio-Claudian dynasty. Nero was adopted by his great-uncle Claudius to become his heir and successor, and succeeded to the throne in 54 following Claudius' death....

(54–68 AD) as an adjunct to his villa on the Aniene
Aniene
-External links:* http://www.humnet.ucla.edu/humnet/horaces-villa/glossary/Anio.gloss.html*...

river, the three reservoirs were highly unusual in their time for serving recreational rather than utilitarian purposes. The biggest dam of the group is estimated to have reached a height of 50 m. It remained unsurpassed in the world until its accidental destruction in 1305 by two monks who fatally removed cover stones from the top. Also quite tall structures were Almonacid de la Cuba Dam
Almonacid de la Cuba Dam
The Almonacid de la Cuba Dam was a Roman gravity dam in Almonacid de la Cuba, Zaragoza province, Aragon, Spain, dating to the 1st century AD.- See also :* List of Roman dams and reservoirs* Roman architecture* Roman engineering- External links :*...

(34 m), Cornalvo Dam
Cornalvo Dam
The Cornalvo Dam is a Roman gravity dam in Badajoz province, Extremadura, Spain, dating to the 1st or 2nd century AD. The earth dam with stone cladding on the water face is still in use.- See also :* List of Roman dams and reservoirs* Roman architecture...

(28 m) and Proserpina Dam
Proserpina Dam
The Proserpina Dam is a Roman gravity dam in Badajoz , Extremadura, Spain, dating to the 1st or 2nd century AD. It was built as part of the infrastructure which supplied the city of Emerita Augusta with water....

(21.6 m), all of which are located in Spain and still of substantially Roman fabric.

Domes

The largest dome in the world for more than 1,700 years was the Pantheon
Pantheon, Rome
The Pantheon ,Rarely Pantheum. This appears in Pliny's Natural History in describing this edifice: Agrippae Pantheum decoravit Diogenes Atheniensis; in columnis templi eius Caryatides probantur inter pauca operum, sicut in fastigio posita signa, sed propter altitudinem loci minus celebrata.from ,...

in Rome. Its concrete dome
Dome
A dome is a structural element of architecture that resembles the hollow upper half of a sphere. Dome structures made of various materials have a long architectural lineage extending into prehistory....

spans an interior space of 43.45 m, which corresponds exactly to its height from floor to top. Its apex concludes with a 8.95 m wide oculus
Oculus
An Oculus, circular window, or rain-hole is a feature of Classical architecture since the 16th century. They are often denoted by their French name, oeil de boeuf, or "bull's-eye". Such circular or oval windows express the presence of a mezzanine on a building's façade without competing for...

. The structure remained unsurpassed until 1881 and stills holds the title of the largest unreinforced solid concrete dome in the world. The Pantheon has exercised an immense influence on Western
Western world
The Western world, also known as the West and the Occident , is a term referring to the countries of Western Europe , the countries of the Americas, as well all countries of Northern and Central Europe, Australia and New Zealand...

dome construction to this day.

The largest dome out of clay hollowware ever constructed is the Caldarium
Caldarium
right|thumb|230px|Caldarium from the Roman Baths at [[Bath, England]]. The floor has been removed to reveal the empty space where the hot air flowed through to heat the floor....

of the Baths of Caracalla
Baths of Caracalla
The Baths of Caracalla in Rome, Italy were Roman public baths, or thermae, built in Rome between AD 212 and 216, during the reign of the Emperor Caracalla.- History :...

in Rome. The now ruined dome, completed in 216 AD, had an inner diameter of 35.08 m. For reduction of weight its shell was constructed of amphora
Amphora
An amphora is a type of vase-shaped, usually ceramic container with two handles and a long neck narrower than the body...

joined together, a quite new method then which could do without time-consuming wooden centring
Centring
Centring , or centering , is the structure upon which the stones of arches or vault are laid during construction. Once the arch is complete, it supports itself, but until the keystone is inserted, it has no strength and needs the centring to keep the voussoirs in their correct relative...

.

The largest half-domes were found in the Baths of Trajan
Baths of Trajan
The Baths of Trajan were a massive thermae, a bathing and leisure complex, built in ancient Rome starting from 104 AD and dedicated during the Kalends of July in 109...

in Rome, completed in 109 AD. Several exedra
Exedra
In architecture, an exedra is a semicircular recess or plinth, often crowned by a semi-dome, which is sometimes set into a building's facade. The original Greek sense was applied to a room that opened onto a stoa, ringed with curved high-backed stone benches, a suitable place for a philosophical...

e integrated into the enclosure wall of the compound reached spans up to 30 m.

The largest stone dome was the Western Thermae in Gerasa, Jordan
Jordan
Jordan , officially the Hashemite Kingdom of Jordan , Al-Mamlaka al-Urduniyya al-Hashemiyya) is a kingdom on the East Bank of the River Jordan. The country borders Saudi Arabia to the east and south-east, Iraq to the north-east, Syria to the north and the West Bank and Israel to the west, sharing...

, constructed around 150/175 AD. The 15 m wide dome of the bath complex was also one of the earliest of its kind with a square ground plan.

Fortifications

The longest city walls were those of Classical Athens
Classical Athens
The city of Athens during the classical period of Ancient Greece was a notable polis of Attica, Greece, leading the Delian League in the Peloponnesian War against Sparta and the Peloponnesian League. Athenian democracy was established in 508 BC under Cleisthenes following the tyranny of Hippias...

. Their extraordinary length was due to the construction of the famous Long Walls
Long Walls
The Long Walls , in Ancient Greece, were walls built from a city to its port, providing a secure connection to the sea even during times of siege. Although long walls were built at several locations in Greece—Corinth and Megara being two of the best known examples—the phrase "long...

which played a key role in the city's maritime strategy, by providing it with a secure access to the sea and offering the population of Attica
Attica
Attica is a historical region of Greece, containing Athens, the current capital of Greece. The historical region is centered on the Attic peninsula, which projects into the Aegean Sea...

a retreat zone in case of foreign invasions. At the eve of the Peloponnesian War
Peloponnesian War
The Peloponnesian War, 431 to 404 BC, was an ancient Greek war fought by Athens and its empire against the Peloponnesian League led by Sparta. Historians have traditionally divided the war into three phases...

(431–404 BC), Thucydides
Thucydides
Thucydides was a Greek historian and author from Alimos. His History of the Peloponnesian War recounts the 5th century BC war between Sparta and Athens to the year 411 BC...

gave the length of the entire circuit as follows: 43 stades (7.6 km) for the city walls without the southwestern section covered by others walls and 60 stades (10.6 km) for the circumference of the Peiraeus port. A corridor between these two was established by the northern Long Wall (40 stades or 7.1 km) and the Phaleric Wall (35 stades or 6.2 km). Assuming a value of 177.6 m for one Attic stade, the overall length of the walls of Athens thus measured about 31.6 km. The structure, consisting of sun-dried bricks built on a foundation of limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

blocks, was dismantled after Athens’ defeat in 404 BC, but rebuilt a decade later. Syracuse, Rome (Aurelian Walls
Aurelian Walls
The Aurelian Walls is a line of city walls built between 271 and 275 in Rome, Italy, during the reign of the Roman Emperors Aurelian and Probus....

) and Constantinople (Walls of Constantinople
Walls of Constantinople
The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople since its founding as the capital of the Eastern Roman Empire by Constantine the Great...

) were also protected by very long circuit walls.

Monoliths

The largest monolith
Monolith
A monolith is a geological feature such as a mountain, consisting of a single massive stone or rock, or a single piece of rock placed as, or within, a monument...

lifted by a single crane can be determined from the characteristic lewis iron
Lewis (Lifting appliance)
A lewis is one of a category of lifting devices used by stonemasons to lift large stones into place with a crane, chain block, or winch. It is inserted into a specially prepared hole, or seating, in the top of a stone, directly above its centre of mass...

holes (each of which points at the use of one crane) in the lifted stone block. By dividing its weight by their number, one arrives at a maximum lifting capacity of 7.5 to 8 t as exemplified by a cornice
Cornice
Cornice molding is generally any horizontal decorative molding that crowns any building or furniture element: the cornice over a door or window, for instance, or the cornice around the edge of a pedestal. A simple cornice may be formed just with a crown molding.The function of the projecting...

block at the Trajan's Forum
Trajan's Forum
Trajan's Forum is an ancient structure in Rome, Italy, chronologically the last of the Imperial fora. The forum was constructed by the architect Apollodorus of Damascus.-History:...

and the architrave
Architrave
An architrave is the lintel or beam that rests on the capitals of the columns. It is an architectural element in Classical architecture.-Classical architecture:...

blocks of the Temple of Jupiter at Baalbek. Based on a detailed Roman relief
Relief
Relief is a sculptural technique. The term relief is from the Latin verb levo, to raise. To create a sculpture in relief is thus to give the impression that the sculpted material has been raised above the background plane...

of a construction crane, the engineer O'Connor calculates a slightly less lifting capability, 6.2 t, for such a type of treadwheel crane
Treadwheel crane
A treadwheel crane is a wooden, human powered, hoisting and lowering device. It was primarily used during Roman times and the Middle Ages in the building of castles and cathedrals. The often heavy charge is lifted as the individual inside the treadwheel crane walks...

, on the assumption that it was powered by five men and using a three-pulley
Pulley
A pulley, also called a sheave or a drum, is a mechanism composed of a wheel on an axle or shaft that may have a groove between two flanges around its circumference. A rope, cable, belt, or chain usually runs over the wheel and inside the groove, if present...

block.

The largest monolith lifted by cranes was the 108 t heavy corner cornice block of the Jupiter temple at Baalbek, followed by an architrave block weighing 63 t, both of which were raised to a height of about 19 m. The capital block of Trajan's Column
Trajan's Column
Trajan's Column is a Roman triumphal column in Rome, Italy, which commemorates Roman emperor Trajan's victory in the Dacian Wars. It was probably constructed under the supervision of the architect Apollodorus of Damascus at the order of the Roman Senate. It is located in Trajan's Forum, built near...

, with a weight of 53.3 t, was even lifted to ca. 34 m above the ground. As such enormous loads far exceeded the lifting capability of any single treadwheel crane, it is assumed that Roman engineers set up a four-masted lifting tower in the midst of which the stone blocks were vertically raised by the means of capstans
Capstan (nautical)
A capstan is a vertical-axled rotating machine developed for use on sailing ships to apply force to ropes, cables, and hawsers. The principle is similar to that of the windlass, which has a horizontal axle.- History :...

placed on the ground around it.

The largest monoliths hewn were two giant building blocks in the quarry of Baalbek: an unnamed rectangular block which was only recently discovered is measured at ca. 20 m x 4.45 m x 4.5 m, yielding a weight of 1,242 t. The similarly shaped Stone of the Pregnant Woman
Stone of the Pregnant Woman
The Stone of the Pregnant Woman or Stone of the South is a Roman monolith in Baalbek , Lebanon. Together with another ancient stone block nearby, it is among the very largest monoliths ever quarried by men...

nearby weighs an estimated 1,000.12 t. Both limestone blocks were intended for the Roman temple district nearby, possibly as an addition to the trilithon, but were left for unknown reasons at their quarrying sites.

The largest monolith moved was the trilithon, a group of three monumental blocks in the podium of the Jupiter temple at Baalbek. The individual stones are 19.60 m, 19.30 m and 19.10 m long respectively, with a depth of 3.65 m and a height of 4.34 m. Weighing approximately 800 t on average, they were transported a distance of 800 m from the quarry and probably pulled by the means of ropes and capstans into their final position. The supporting stone layer beneath features a number of blocks which are still in the order of 350 t. The various giant stones of Roman Baalbek rank high among the largest man-made monoliths in history.

The largest monolithic column
Monolithic column
A monolithic column is a column of which the shaft is made from one single piece of stone instead of different sections.They are sometimes called 'single-piece columns' and were most likely used on ancient temples....

s were used by Roman builders who preferred them over the stacked drums typical of classical Greek architecture. The logistics and technology involved in the transport and erection of extra-large single-piece columns were demanding: As a rule of thumb, the weight of the column shafts in the length range between 40 and 60 Roman feet (ca. 11.8 to 17.8 m) doubled with every ten feet from ca. 50 over 100 to 200 t. Despite this, forty and also fifty feet tall monolithic shafts can be found in a number of Roman buildings, but examples reaching sixty feet are only in evidence in two unfinished granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...

columns which still lie in the Roman quarry of Mons Claudianus
Mons Claudianus
Mons Claudianus was a Roman quarry in the eastern desert of Egypt. It consisted of a garrison, a quarrying site and civilian and workers quarters.Granodiorite was mined for the Roman Empire where it was used as a building material...

, Egypt. One of the pair, which was discovered only in the 1930s, has an estimated weight of 207 t. All these dimensions, however, are surpassed by Pompey's Pillar
Pompey's Pillar (column)
Pompey's Pillar is a Roman triumphal column in Alexandria, Egypt, and the largest of its type constructed outside of the imperial capitals of Rome and Constantinople...

, a free-standing victory column erected in Alexandria
Alexandria
Alexandria is the second-largest city of Egypt, with a population of 4.1 million, extending about along the coast of the Mediterranean Sea in the north central part of the country; it is also the largest city lying directly on the Mediterranean coast. It is Egypt's largest seaport, serving...

in 297 AD: measuring 20.46 m high with a diameter of 2.71 m at its base, the weight of its granite shaft has been put at 285 t.

The largest monolithic dome crowned the early 6th century AD Mausoleum of Theodoric
Mausoleum of Theodoric
The Mausoleum of Theodoric is an ancient monument just outside Ravenna, Italy. It was built in 520 AD by Theodoric the Great as his future tomb.-Description:...

in Ravenna
Ravenna
Ravenna is the capital city of the Province of Ravenna in the Emilia-Romagna region of Italy and the second largest comune in Italy by land area, although, at , it is little more than half the size of the largest comune, Rome...

, then capital of the Ostrogothic kingdom
Ostrogothic Kingdom
The Kingdom established by the Ostrogoths in Italy and neighbouring areas lasted from 493 to 553. In Italy the Ostrogoths replaced Odoacer, the de facto ruler of Italy who had deposed the last emperor of the Western Roman Empire in 476. The Gothic kingdom reached its zenith under the rule of its...

. The weight of the single, 10.76 m wide roof slab has been calculated at 230 t.

Obelisks

The tallest obelisks are all located in Rome, adorning its inner-city squares. The Agonalis obelisk on Piazza Navona
Piazza Navona
Piazza Navona is a city square in Rome, Italy. It is built on the site of the Stadium of Domitian, built in 1st century AD, and follows the form of the open space of the stadium. The ancient Romans came there to watch the agones , and hence it was known as 'Circus Agonalis'...

stands highest at 16.54 m without pedestal
Pedestal
Pedestal is a term generally applied to the support of a statue or a vase....

, followed by the Esquiline, Quirinale (both 14.7 m), Sallustiano (13.92 m) and the somewhat smaller Pinciano obelisk. Only some of them were inscribed with hieroglyph
Egyptian hieroglyphs
Egyptian hieroglyphs were a formal writing system used by the ancient Egyptians that combined logographic and alphabetic elements. Egyptians used cursive hieroglyphs for religious literature on papyrus and wood...

s, while others remained blank. These five obelisks of Roman date complement a group of eight ancient Egyptian obelisks which were carried on imperial order by obelisk carriers from the Nile to the Tiber
Tiber
The Tiber is the third-longest river in Italy, rising in the Apennine Mountains in Emilia-Romagna and flowing through Umbria and Lazio to the Tyrrhenian Sea. It drains a basin estimated at...

, elevating Rome to the city with the most ancient obelisks to this day.

Roads

The longest trackway was the Diolkos
Diolkos
The Diolkos was a paved trackway near Corinth in Ancient Greece which enabled boats to be moved overland across the Isthmus of Corinth. The shortcut allowed ancient vessels to avoid the dangerous circumnavigation of the Peloponnese peninsula...

near Corinth
Corinth
Corinth is a city and former municipality in Corinthia, Peloponnese, Greece. Since the 2011 local government reform it is part of the municipality Corinth, of which it is the seat and a municipal unit...

, Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

, measuring between 6 and 8.5 km. The paved roadway allowed boats to be pulled across the Isthmus of Corinth
Isthmus of Corinth
The Isthmus of Corinth is the narrow land bridge which connects the Peloponnese peninsula with the rest of the mainland of Greece, near the city of Corinth. The word "isthmus" comes from the Ancient Greek word for "neck" and refers to the narrowness of the land. The Isthmus was known in the ancient...

, thus avoiding the long and dangerous sea trip around the Peloponnese
Peloponnese
The Peloponnese, Peloponnesos or Peloponnesus , is a large peninsula , located in a region of southern Greece, forming the part of the country south of the Gulf of Corinth...

peninsula. Working by the railway principle, with a gauge
Rail gauge
Track gauge or rail gauge is the distance between the inner sides of the heads of the two load bearing rails that make up a single railway line. Sixty percent of the world's railways use a standard gauge of . Wider gauges are called broad gauge; smaller gauges, narrow gauge. Break-of-gauge refers...

of around 160 cm between two parallel grooves cut into the limestone paving, it remained in regular and frequent service for at least 650 years. By comparison, the world's first overland wagonway, the Wollaton Wagonway
Wollaton Wagonway
The Wollaton Wagonway , built between October 1603 and 1604 in the East Midlands of England by Huntingdon Beaumont in partnership with Sir Percival Willoughby, is currently credited as the world's first overland wagonway and is therefore regarded as a significant step in the development of...

of 1604, ran for ca. 3 km.

Roofs

The largest prop-and-lintel roof by span spanned the Parthenon
Parthenon
The Parthenon is a temple on the Athenian Acropolis, Greece, dedicated to the Greek goddess Athena, whom the people of Athens considered their virgin patron. Its construction began in 447 BC when the Athenian Empire was at the height of its power. It was completed in 438 BC, although...

in Athens
Athens
Athens , is the capital and largest city of Greece. Athens dominates the Attica region and is one of the world's oldest cities, as its recorded history spans around 3,400 years. Classical Athens was a powerful city-state...

. It measured 19.20 m between the cella
Cella
A cella or naos , is the inner chamber of a temple in classical architecture, or a shop facing the street in domestic Roman architecture...

walls, with an unsupported span of 11.05 m between the interior colonnades. Sicilian
Magna Graecia
Magna Græcia is the name of the coastal areas of Southern Italy on the Tarentine Gulf that were extensively colonized by Greek settlers; particularly the Achaean colonies of Tarentum, Crotone, and Sybaris, but also, more loosely, the cities of Cumae and Neapolis to the north...

temples of the time featured slightly larger cross sections, but these may have been covered by truss roofs instead.

The largest truss roof by span covered the Aula Regia
Flavian Palace
The Flavian Palace, also known as Domus Flavia, is a part of the vast residential complex of the Roman Emperors on the Palatine Hill in Rome...

(throne room) built for emperor Domitian
Domitian
Domitian was Roman Emperor from 81 to 96. Domitian was the third and last emperor of the Flavian dynasty.Domitian's youth and early career were largely spent in the shadow of his brother Titus, who gained military renown during the First Jewish-Roman War...

(81–96 AD) on the Palatine Hill
Palatine Hill
The Palatine Hill is the centermost of the Seven Hills of Rome and is one of the most ancient parts of the city...

, Rome. The timber truss roof had a width of 31.67 m, slightly surpassing the postulated limit of 30 m for Roman roof constructions. Tie-beam trusses allowed for much larger spans than the older prop-and-lintel system and even concrete vaulting: Nine out of the ten largest rectangular spaces in Roman architecture were bridged this way, the only exception being the groin vaulted Basilica of Maxentius
Basilica of Maxentius
The Basilica of Maxentius and Constantine is an ancient building in the Roman Forum, Rome, Italy...

.

Tunnels

The deepest tunnel was the Claudius Tunnel, constructed in eleven years time by emperor Claudius
Claudius
Claudius , was Roman Emperor from 41 to 54. A member of the Julio-Claudian dynasty, he was the son of Drusus and Antonia Minor. He was born at Lugdunum in Gaul and was the first Roman Emperor to be born outside Italy...

(41–54 AD). Draining the Fucine Lake
Fucine Lake
The Fucine Lake was a large lake in central Italy, stretching from Avezzano in the northwest to Ortuccio in the southeast, and touching Trasacco in the southwest. It was drained in 1875.-Roman drainage:...

, the largest Italian inland water, 100 km east of Rome, it is widely deemed as the most ambitious Roman tunnel project as it stretched ancient technology to its limits. The 5653 m long qanat
Qanat
A qanāt is a water management system used to provide a reliable supply of water for human settlements and irrigation in hot, arid and semi-arid climates...

tunnel, passing under Monte Salviano, features vertical shafts up to 122 m depth; even longer ones were run obliquely through the rock. After repairs under Trajan
Trajan
Trajan , was Roman Emperor from 98 to 117 AD. Born into a non-patrician family in the province of Hispania Baetica, in Spain Trajan rose to prominence during the reign of emperor Domitian. Serving as a legatus legionis in Hispania Tarraconensis, in Spain, in 89 Trajan supported the emperor against...

and Hadrian
Hadrian
Hadrian , was Roman Emperor from 117 to 138. He is best known for building Hadrian's Wall, which marked the northern limit of Roman Britain. In Rome, he re-built the Pantheon and constructed the Temple of Venus and Roma. In addition to being emperor, Hadrian was a humanist and was philhellene in...

, the Claudius tunnel remained in use until the end of antiquity. Various attempts at restoration succeeded only in the late 19th century.

The longest road tunnel was the Cocceius Tunnel
Grotta di Cocceio
Grotta di Cocceio, also known as the Cocceius Tunnel, is a straight-line subterranean gallery nearly a kilometre in length connecting Lake Avernus with Cumae north of Naples, Italy. It was burrowed clean through the tuff stone of Monte Grillo from 38-36 BCE...

near Naples
Naples
Naples is a city in Southern Italy, situated on the country's west coast by the Gulf of Naples. Lying between two notable volcanic regions, Mount Vesuvius and the Phlegraean Fields, it is the capital of the region of Campania and of the province of Naples...

, Italy, which connected Cumae
Cumae
Cumae is an ancient Greek settlement lying to the northwest of Naples in the Italian region of Campania. Cumae was the first Greek colony on the mainland of Italy , and the seat of the Cumaean Sibyl...

with the base of the Roman fleet
Roman Navy
The Roman Navy comprised the naval forces of the Ancient Roman state. Although the navy was instrumental in the Roman conquest of the Mediterranean basin, it never enjoyed the prestige of the Roman legions...

, Portus Julius
Portus Julius
Portus Julius was the home port for the Roman western imperial fleet, the classis Misenensis, named for nearby Cape Miseno...

. The 1000 m long tunnel was part of an extensive underground network which facilitated troop movements between the various Roman facilities in the volcanic area. Built by the architect Cocceius Auctus
Cocceius Auctus
Lucius Cocceius Auctus was a Roman architect employed by Octavian's strategist Agrippa to excavate the subterranean passageways the crypta neapolitana connecting modern-day Naples and Pozzuoli and the Grotta di Cocceio connecting Lake Avernus and Cumae...

, it featured paved access roads and well-built mouthes. Other road tunnels include the Crypta Neapolitana to Pozzuoli
Pozzuoli
Pozzuoli is a city and comune of the province of Naples, in the Italian region of Campania. It is the main city of the Phlegrean peninsula.-History:Pozzuoli began as the Greek colony of Dicaearchia...

(750 m long, 3–4 m wide and 3–5 m high), and the similarly sized Grotta di Seiano.

The longest qanat
Qanat
A qanāt is a water management system used to provide a reliable supply of water for human settlements and irrigation in hot, arid and semi-arid climates...

was the 94 km long Gadara Aqueduct
Gadara Aqueduct
The Gadara Aqueduct was an Roman aqueduct to supply water to the city of Gadara, modern-day Jordan, and the longest known tunnel of antiquity. The 170 km long pipeline was constructed in the qanat technology, that is as a series of well-like vertical shafts, which were connected underground from...

in northern Jordan
Jordan
Jordan , officially the Hashemite Kingdom of Jordan , Al-Mamlaka al-Urduniyya al-Hashemiyya) is a kingdom on the East Bank of the River Jordan. The country borders Saudi Arabia to the east and south-east, Iraq to the north-east, Syria to the north and the West Bank and Israel to the west, sharing...

. This recently discovered structure provided for hundreds of years water for Adraa, Abila
Abila (Decapolis)
Abila Dekapoleos – Abila in the Decapolis or Abila was an ancient city, near the Hieromax river in the Decapolis; the site is occupied by two tells and the village of Hartha, circa north-northeast of Irbid, Jordan. The site is 25km east of the Sea of Galilee and 4km south of Wadi Yarmouk...

and Gadara, three cities of the ancient Decapolis
Decapolis
The Decapolis was a group of ten cities on the eastern frontier of the Roman Empire in Judea and Syria. The ten cities were not an official league or political unit, but they were grouped together because of their language, culture, location, and political status...

. Only 35 km long as the crow flies, its length was almost tripled by following closely the contours of the local topography, avoiding valleys and mountain ridges alike. The monumental work seemed to be carried out in seven stages of construction between 130 and 193 AD. The distance between the individual vertical shafts was on average 50 m. Probably the project was initiated by Hadrian
Hadrian
Hadrian , was Roman Emperor from 117 to 138. He is best known for building Hadrian's Wall, which marked the northern limit of Roman Britain. In Rome, he re-built the Pantheon and constructed the Temple of Venus and Roma. In addition to being emperor, Hadrian was a humanist and was philhellene in...

, who had granted privileges to the cities during a longer stay in the Decapolis. The aqueduct remained operational until the Byzantines
Byzantine Empire
The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

lost control of the region after the Battle of Yarmuk in 636.

The longest tunnel excavated from opposite ends was built around the end of the 6th century BC for draining and regulating Lake Nemi
Lake Nemi
Lake Nemi is a small circular volcanic lake in the Lazio region of Italy south of Rome, taking its name from Nemi, the largest town in the area, that overlooks it from a height.-Archaeology and history:The lake is most famous for its sunken Roman ships...

, Italy. Measuring 1600 m, it was almost 600 m longer than the slightly older Tunnel of Eupalinos on the isle of Samos
Samoš
Samoš is a village in Serbia. It is situated in the Kovačica municipality, in the South Banat District, Vojvodina province. The village has a Serb ethnic majority and its population numbering 1,247 people .-See also:...

, the first tunnel in history to be excavated from two ends with a methodical approach. The Albano Tunnel, also in central Italy, reaches a length of 1,400 m. It was excavated no later than 397 BC and is still in service. Determining the tunnelling direction underground and coordinating the advance of the separate work parties made meticulous surveying and execution on the part of the ancient engineers necessary.

Vaulting

The largest barrel vault
Barrel vault
A barrel vault, also known as a tunnel vault or a wagon vault, is an architectural element formed by the extrusion of a single curve along a given distance. The curves are typically circular in shape, lending a semi-cylindrical appearance to the total design...

by span covered the Temple of Venus and Roma
Temple of Venus and Roma
The Temple of Venus and of Rome — in Latin, Templum Veneris et Romae — is thought to have been the largest temple in Ancient Rome. Located on the Velian Hill, between the eastern edge of the Forum Romanum and the Colosseum, it was dedicated to the goddesses Venus Felix and Roma Aeterna...

, Rome. Built between 307 and 312 AD, the vaulted structure replaced the original timber truss roof from Hadrian
Hadrian
Hadrian , was Roman Emperor from 117 to 138. He is best known for building Hadrian's Wall, which marked the northern limit of Roman Britain. In Rome, he re-built the Pantheon and constructed the Temple of Venus and Roma. In addition to being emperor, Hadrian was a humanist and was philhellene in...

’s time.

The largest groin vault
Groin vault
A groin vault or groined vault is produced by the intersection at right angles of two barrel vaults. The word groin refers to the edge between the intersecting vaults; cf. ribbed vault. Sometimes the arches of groin vaults are pointed instead of round...

by span roofed the 25.01 m wide main nave of the Basilica of Maxentius
Basilica of Maxentius
The Basilica of Maxentius and Constantine is an ancient building in the Roman Forum, Rome, Italy...

on the Forum Romanum, built in the early 4th century AD.

Miscellaneous

The greatest concentration of mechanical power was the Barbegal water mill complex
Barbegal aqueduct and mill
The Barbegal aqueduct and mill is a Roman watermill complex located on the territory of the commune of Fontvieille, near the town of Arles, in southern France. The complex has been referred to as "the greatest known concentration of mechanical power in the ancient world"...

in southern France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, constructed in the early 2nd century AD. Sixteen overshot water wheel
Water wheel
A water wheel is a machine for converting the energy of free-flowing or falling water into useful forms of power. A water wheel consists of a large wooden or metal wheel, with a number of blades or buckets arranged on the outside rim forming the driving surface...

s fed by an arcaded aqueduct
Aqueduct
An aqueduct is a water supply or navigable channel constructed to convey water. In modern engineering, the term is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose....

branch from the main conduit to Arles
Arles
Arles is a city and commune in the south of France, in the Bouches-du-Rhône department, of which it is a subprefecture, in the former province of Provence....

produced an estimated 4.5 t of flour
Flour
Flour is a powder which is made by grinding cereal grains, other seeds or roots . It is the main ingredient of bread, which is a staple food for many cultures, making the availability of adequate supplies of flour a major economic and political issue at various times throughout history...

per 24 hours – an output sufficient to feed 12,500 people or the majority of the population of Arles. Water mill batteries are also known from Amida
Diyarbakır
Diyarbakır is one of the largest cities in southeastern Turkey...

in Asia Minor, the Janiculum
Janiculum
The Janiculum is a hill in western Rome, Italy. Although the second-tallest hill in the contemporary city of Rome, the Janiculum does not figure among the proverbial Seven Hills of Rome, being west of the Tiber and outside the boundaries of the ancient city.-Sights:The Janiculum is one of the...

hill in Rome, and a number of other places throughout the empire
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....

.

The longest spiral stair
Stairway
Stairway, staircase, stairwell, flight of stairs, or simply stairs are names for a construction designed to bridge a large vertical distance by dividing it into smaller vertical distances, called steps...

belonged to the 2nd century AD Trajan's Column
Trajan's Column
Trajan's Column is a Roman triumphal column in Rome, Italy, which commemorates Roman emperor Trajan's victory in the Dacian Wars. It was probably constructed under the supervision of the architect Apollodorus of Damascus at the order of the Roman Senate. It is located in Trajan's Forum, built near...

in Rome. Measuring a height of 29.68 m, it surpassed its successor, the Column of Marcus Aurelius, by a mere 6 cm. Its treads were carved out ouf nineteen massive marble blocks so that each drum comprised a half-turn of seven steps. The quality of the craftsmanship was such that the staircase was practically even, and the joints between the huge blocks accurately fitting. The design of the Trajan’s column had a profound influence on Roman construction technique, and the spiral stair became over time an establish architectural element.

The longest straight alignment was constituted by a 81.259 km long section of the Roman limes
Limes Germanicus
The Limes Germanicus was a line of frontier fortifications that bounded the ancient Roman provinces of Germania Inferior, Germania Superior and Raetia, dividing the Roman Empire and the unsubdued Germanic tribes from the years 83 to about 260 AD...

in Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

. The fortified line ran through hilly and densely wooded country in completely linear fashion, deviating in its entire length only once, for a distance of 1.6 km, to avoid a steep valley. The extraordinary accuracy of the alignment has been attributed to the groma
Groma surveying
The Groma or gruma was the principal Roman surveying instrument. It comprised a vertical staff with horizontal cross pieces mounted at right-angles on a bracket. Each cross piece had a plumb line hanging vertically at each end...

, a surveying instrument which was used by the Romans to great effect in land division and road construction.

External links

Traianus – Technical investigation of Roman public works
600 Roman Aqueducts – with 40 described in detail

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