Avernus was an ancient name for a crater near 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...

 (Cuma), Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

, in the Region of Campania

Campania

Campania is a region in southern Italy. The region has a population of around 5.8 million people, making it the second-most-populous region of Italy; its total area of 13,590 km² makes it the most densely populated region in the country...

 west of 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...

. It is approximately 3.2 kilometres (2 mi) in circumference. Within the crater is Lake Avernus

Lake Avernus

Lake Avernus is a volcanic crater lake located in the Avernus crater in the Campania region of southern Italy, around northwest of Pozzuoli. It is near the volcanic field known as the Campi Flegrei and comprises part of the wider Campanian volcanic arc...

 (Lago d'Averno).

Role in ancient Roman society

Avernus was believed

Roman mythology

Roman mythology is the body of traditional stories pertaining to ancient Rome's legendary origins and religious system, as represented in the literature and visual arts of the Romans...

 to be the entrance to the underworld

Hades

Hades , Hadēs, originally , Haidēs or , Aidēs , meaning "the unseen") was the ancient Greek god of the underworld. The genitive , Haidou, was an elision to denote locality: "[the house/dominion] of Hades". Eventually, the nominative came to designate the abode of the dead.In Greek mythology, Hades...

, and is portrayed as such in the Aeneid

Aeneid

The Aeneid is a Latin epic poem, written by Virgil between 29 and 19 BC, that tells the legendary story of Aeneas, a Trojan who travelled to Italy, where he became the ancestor of the Romans. It is composed of roughly 10,000 lines in dactylic hexameter...

of Virgil

Virgil

Publius Vergilius Maro, usually called Virgil or Vergil in English , was an ancient Roman poet of the Augustan period. He is known for three major works of Latin literature, the Eclogues , the Georgics, and the epic Aeneid...

. The name comes from the Greek word άορνος, meaning "without birds", because according to tradition, all birds flying over the lake were destined to fall dead. This was likely due to the toxic fumes that mouths of the crater gave off into the atmosphere. In later times, the word was simply an alternate name for the underworld

Hades

Hades , Hadēs, originally , Haidēs or , Aidēs , meaning "the unseen") was the ancient Greek god of the underworld. The genitive , Haidou, was an elision to denote locality: "[the house/dominion] of Hades". Eventually, the nominative came to designate the abode of the dead.In Greek mythology, Hades...

. On the shores of the lake is the grotto of the Cumaean Sybil and the entrance to a long tunnel (Grotta di Cocceio

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...

, ca. 800 metres (2,624.7 ft)) leading toward Cumae, where her sanctuary was located. There are also the remains of temples to Apollo

Apollo

Apollo is one of the most important and complex of the Olympian deities in Greek and Roman mythology...

 and Jupiter.
During the civil war between Octavian

Augustus

Augustus ;23 September 63 BC – 19 August AD 14) is considered the first emperor of the Roman Empire, which he ruled alone from 27 BC until his death in 14 AD.The dates of his rule are contemporary dates; Augustus lived under two calendars, the Roman Republican until 45 BC, and the Julian...

 and Antony

Antony

Antony is an English language variant of Anthony. It can refer to:People* Mark Antony, Roman politician and general* Antony Flew, a contemporary British philosopher* Antony Gormley, a contemporary British sculptor...

, Agrippa tried to turn the lake into a military port, the Portus Julius

Portus Julius

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

. A waterway was dug from Lake Lucrino

Lucrinus Lacus

Lucrinus Lacus, or Luctrin Lake is a lake of Campania, southern Italy, about three kilometres to the south of Lake Avernus....

 to Avernus to this end. The port's remains may still be seen under the lake's surface.

Averni

The term Avernus (plural Averni) was also used by ancient naturalists for certain lakes, grottos, and other places which infect the air with poisonous steams or vapors. They were said to be frequent in Hungary

Hungary

Hungary , officially the Republic of Hungary , is a landlocked country in Central Europe. It is situated in the Carpathian Basin and is bordered by Slovakia to the north, Ukraine and Romania to the east, Serbia and Croatia to the south, Slovenia to the southwest and Austria to the west. The...

 on account of the abundance of mines there. The Grotto dei Cani in Italy was a famous example. The most celebrated of these, however, is Lake Avernus.

They were also called mephites. Mephitis

Mefitis

In Roman mythology, Mefitis was the personification of the poisonous gases emitted from the ground in swamps and volcanic vapors....

 was the Roman goddess of noxious vapors, who protects against malaria. The adjective "mephitic" means "foul-smelling" or "malodorous".

See also

• Ploutonion
  Ploutonion
  In ancient Greek religious topography, a Ploutonion , Latinized as Plutonium, was a sanctuary dedicated to the god Plouton , often in a location that produced mephitic emanations and thus representing an entrance to the Underworld....
  
  , "grotto of Plouton
  Pluto (mythology)
  In ancient Greek religion and myth, Pluto was a name for the ruler of the underworld; the god was also known as Hades, a name for the underworld itself...
  
  ," a Greek term for a mephitic sanctuary