Caves of the Tullybrack and Belmore hills
Encyclopedia
The Caves of the Tullybrack and Belmore hills can be found in south-west County Fermanagh
, Northern Ireland
. It is mainly within Boho parish. The region is also described as the West Fermanagh Scarplands by environmental agencies and shares many similar karst
features with the nearby Marble Arch Caves Global Geopark
.
The caves are situated under the hills of Tullybrack (386 m (1,266.4 ft)) – which incorporates Glenkeel (373 m (1,223.8 ft)) and Knockmore
(280 m (918.6 ft)) – and Belmore
(398 m (1,305.8 ft)) and feature three major cave systems: Reyfad
–Glenkeel, Noon's Hole
–Arch Cave and Boho Caves
. They have been described as nationally significant by the Northern Ireland Environment Agency.
The caves and related features are formed predominantly in the Dartry Limestone Formation - a sequence of rocks assigned to the Asbian sub-stage of the Visean
stage of the Carboniferous
period. Within this Formation, the Knockmore Limestone Member is also an important cave forming rock sequence. Cave development has occurred within the Quaternary
period and certain features are ascribed to the Holocene
epoch
of the last 10,000 years.
With the exception of Arch Cave, all of the caves and related karstic
features listed below have been designated as provisional Areas of Special Scientific Interest
(provisional ASSIs or PASSI's) - a conservation designation
in Northern Ireland equivalent to SSSI's in other parts of the United Kingdom.
epoch of the Quaternary
period and is composed of limestone
. There are two passages in this cave estimated to be about 8 m (26.2 ft) long, one of which has been enlarged as a souterrain
and is also a scheduled ancient monument.
, and some calcite
formations. The cave can be entered by a previously collapsed roof structure through which a large waterfall flows. The stream runs through the cave until it comes to a boulder choke which has so far proved to be impenetrable. The stream resurfaces onto the valley floor of the Aghanaglack River 1.8 km to the west north west.
Pictures of Pollnagollum Coolarkan on Flickr: http://www.flickr.com/photos/stephen_paskin/tags/coolarkan/
–Carrickbeg system, containing a number of very impressive features. The Northern Ireland Environmental Agency describe this system as follows: "the quality of geomorphological and geological features in the Reyfad–Pollnacrom–Polltullybrack cave system make it arguably the most important underground karst site in Northern Ireland."
Carrickbeg Rising is the proven resurgence of four major stream sinks within the system: Pollnacrom, Polltullybrack, Waterfall Sink and Watson's Sink.
-choked hole.
s. A small stream flows into the sinkhole, which is estimated to be 10 m deep. It has been determined that the water from this hole emerges at Carrickbeg Rising.
, which itself is completely blocked up with silt. Above this is a very high roofed chamber or aven
.
Murphy's Hole is situated at the north end of a depression that also contains Seltanacool Sinks. A waterfall drains into the sink, which takes a large volume of water in heavy rains. Water draining here has been dye traced
to the resurgence at Carrickbeg.
This cave is linked to a series of springs. The longest passage here is reported to be no more than 15 m (49.2 ft).
and shale
deposits. This formation is thought to have been a cave roof, which has collapsed, normally known as a shakehole. The debris from the collapse has formed what is known as a 'choke hole'. Investigations have determined that the stream which sinks into Pollkeeran rises again 2 km to the north at Carrickbeg Rising Cave.
Extreme caution is advised as this sink is extremely dangerous and attempts to explore should only be undertaken by very experienced cavers.
. This site has been designated a PASSI.
This cave is part of the main Reyfad system that links to the 'Heaven and Hell' passage. It has a small, wet entrance. The cave contains two shafts at 50 and 15 m respectively, which permit entry to the main stream passage which trends in a north-west direction for 100 m (328.1 ft) before turning south. The cave has been explored for 600 m (1,968.5 ft) to an impassable sump. An attempt to force through this route in 1981 led to the death of a diver.
Access is by permission of landowner only.
There is a very tight entrance to this cave through a sinkhole in what is known as a dry valley, but this eventually expands into a wider cave. The continuation of the passage contains many boulders and a deep pool, followed by 250 m of difficult passage which ends in a submerged section, through which cavers have to duck. A short distance beyond this there is a 53-metre shaft, which is the longest-known pitch
of any Irish cave. The cave joins up with the Reyfad system just north of the main chamber. Just before this are chambers known as the 'Grottoes', which contain fine examples of calcite features including stalactite
s, helictite
s and cave curtains.
Access is by permission of landowner only.
. The site, located in moorland, has been designated a PASSI.
Rattle Hole consists of a single shaft of 36 m (118.1 ft) depth, which terminates in a boulder strewn base. This provides access to a second chamber, which is a further 25 m (82 ft) deep and ends in a gravel base. Further efforts at extending this passage have proved fruitless, but as a result of dye testing it is known that the water from here emerges at Carrickbeg.
. Breccia
, chert, calcite and gypsum deposits can also be found.
This cave is noted by the Northern Ireland Environment Agency as being the most important underground karst site in Northern Ireland. At 193 metres (633.2 ft) deep and 6.7 kilometres (4.2 mi) long, it is the deepest cave system in Ireland and the second-longest in Northern Ireland. This site is a PASSI and is a very active cave with many calcite formations and fossiliferous limestone, which includes evidence of Brachiopods and Crinoid
s. The extended area is hypothesised to have formed from the last glacial period (Pleistocene
).
Access is by permission of landowner only.
comprise Dartry and Knockmore Limestones. The site is designated a PASSI.
This sinkhole contains a substantial shaft of 30 m (98.4 ft) depth, with some crawling sections and short passages which ultimately end at an impenetrable crack in the rocks. The stream passing through Aughakeeran is believed to join the drainage through Pollanaffrin.
The cave is named for the art and writing of varying age inscribed on the walls. It was investigated by William Wakeman (1866–70) and Thomas Plunkett (1878 and 1898) and is now a scheduled ancient monument.
This sink is found in a forested area containing a small stream, which sinks in several places. The water from the stream is believed to enter 'Inlet 1' beside 'Artie's Chamber' in the Noon's–Arch system.
A large river enters this pot hole when there is much rain. The cave follows many twists and drops and is of considerable length before it terminates at an impasse. It has been speculated that the water from this system enters Noon's Hole.
County Fermanagh
Fermanagh District Council is the only one of the 26 district councils in Northern Ireland that contains all of the county it is named after. The district council also contains a small section of County Tyrone in the Dromore and Kilskeery road areas....
, Northern Ireland
Northern Ireland
Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...
. It is mainly within Boho parish. The region is also described as the West Fermanagh Scarplands by environmental agencies and shares many similar karst
Karst topography
Karst topography is a geologic formation shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock such as limestone or dolomite, but has also been documented for weathering resistant rocks like quartzite given the right conditions.Due to subterranean drainage, there...
features with the nearby Marble Arch Caves Global Geopark
Marble Arch Caves Global Geopark
The Marble Arch Caves Global Geopark straddles the border between Northern Ireland and the Republic of Ireland. It is centred on the Marble Arch Caves and in 2001 it became one of the first Geoparks to be designated in Europe....
.
The caves are situated under the hills of Tullybrack (386 m (1,266.4 ft)) – which incorporates Glenkeel (373 m (1,223.8 ft)) and Knockmore
Knockmore
Knockmore is an upland area and townland situated in County Fermanagh, Northern Ireland. It is situated outside the village of Derrygonnelly, in the historical barony of Magheraboy. This area, together with most of the adjacent Boho parish is described as the Knockmore Scarplands...
(280 m (918.6 ft)) – and Belmore
Belmore Mountain
Belmore Mountain is a hill in the townland of Gortgall, western County Fermanagh, Northern Ireland. With a summit roughly above sea level, it is the second highest point in Fermanagh, the highest being at Cuilcagh on the Northern Ireland–Republic of Ireland border in the south of the...
(398 m (1,305.8 ft)) and feature three major cave systems: Reyfad
Reyfad
Reyfad is a townland in County Fermanagh, Northern Ireland. It lies in the land division of Old Barr, in the civil parish of BohoThis mountainous townland is well known for its extensive cave system and Neolithic stones.The summit of the nearby hill is known as Tullybrack or Reyfad Mountain but...
–Glenkeel, Noon's Hole
Noon's Hole
Noon's Hole lies about 5 km northwest of the centre of Boho, in the townland of Old Barr in the parish of Devenish, County Fermanagh, close to the border with Boho parish. The cave is under part of the remarkable escarpment on the east side of the Glenade Sandstone uplands...
–Arch Cave and Boho Caves
Boho Caves
The Boho Caves are a selection of caves centred on the village of Boho, County Fermanagh on the northern slopes of Belmore Mountain. They encompass the main Boho Cave and the smaller Waterfall Cave and Upper and Lower Ravine Caves...
. They have been described as nationally significant by the Northern Ireland Environment Agency.
The caves and related features are formed predominantly in the Dartry Limestone Formation - a sequence of rocks assigned to the Asbian sub-stage of the Visean
Viséan
The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from 345.3 ± 2.1 to 328.3 ± 1.6 Ma...
stage of the Carboniferous
Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
period. Within this Formation, the Knockmore Limestone Member is also an important cave forming rock sequence. Cave development has occurred within the Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...
period and certain features are ascribed to the Holocene
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...
epoch
Epoch (geology)
An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...
of the last 10,000 years.
With the exception of Arch Cave, all of the caves and related karstic
KARST
Kilometer-square Area Radio Synthesis Telescope is a Chinese telescope project to which FAST is a forerunner. KARST is a set of large spherical reflectors on karst landforms, which are bowlshaped limestone sinkholes named after the Kras region in Slovenia and Northern Italy. It will consist of...
features listed below have been designated as provisional Areas of Special Scientific Interest
Area of Special Scientific Interest
An Area of Special Scientific Interest or ASSI is a conservation designation denoting a protected area in Northern Ireland. ASSIs are the equivalent of Sites of Special Scientific Interest in the rest of the United Kingdom....
(provisional ASSIs or PASSI's) - a conservation designation
Conservation designation
A conservation designation is a name and/or acronym which explains the status of an area of land in terms of conservation or protection.-United Kingdom:*Area of Outstanding Natural Beauty *Environmentally Sensitive Area*Local Nature Reserve...
in Northern Ireland equivalent to SSSI's in other parts of the United Kingdom.
Boho Caves
Grid Ref: H12684431. The Boho Caves are a selection of caves encompassing the main Boho Cave, the smaller Waterfall Cave and Upper and Lower Ravine Caves. The Boho Cave system is the sixth-longest cave system in Northern Ireland and is the only example of joint-controlled caves in Northern Ireland.Aghnaglack Cave
Grid ref: H108436. This small cave is part of the Boho Cave system and has been designated a Provisional Area of Special Scientific Interest (PASSI) site. The substrata dates from the HoloceneHolocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...
epoch of the Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...
period and is composed 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....
. There are two passages in this cave estimated to be about 8 m (26.2 ft) long, one of which has been enlarged as a souterrain
Souterrain
Souterrain is a name given by archaeologists to a type of underground structure associated mainly with the Atlantic Iron Age. These structures appear to have been brought northwards from Gaul during the late Iron Age. Regional names include earth houses, fogous and Pictish houses...
and is also a scheduled ancient monument.
Aghnaglack Rising
Grid ref: H10884343. This cave is also part of the Boho Cave system and has been designated a PASSI. The substrata date from the Holocene and are composed of limestone. This formation can be crawled through in dry conditions.Pollnagollum, Coolarkan
Grid ref: H12214311. . This site is designated as a PASSI. The rocks comprise Dartry Limestone, chertChert
Chert is a fine-grained silica-rich microcrystalline, cryptocrystalline or microfibrous sedimentary rock that may contain small fossils. It varies greatly in color , but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements...
, and some calcite
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...
formations. The cave can be entered by a previously collapsed roof structure through which a large waterfall flows. The stream runs through the cave until it comes to a boulder choke which has so far proved to be impenetrable. The stream resurfaces onto the valley floor of the Aghanaglack River 1.8 km to the west north west.
Pictures of Pollnagollum Coolarkan on Flickr: http://www.flickr.com/photos/stephen_paskin/tags/coolarkan/
Tullybrack
The second karst system in the Boho area is known as the ReyfadReyfad
Reyfad is a townland in County Fermanagh, Northern Ireland. It lies in the land division of Old Barr, in the civil parish of BohoThis mountainous townland is well known for its extensive cave system and Neolithic stones.The summit of the nearby hill is known as Tullybrack or Reyfad Mountain but...
–Carrickbeg system, containing a number of very impressive features. The Northern Ireland Environmental Agency describe this system as follows: "the quality of geomorphological and geological features in the Reyfad–Pollnacrom–Polltullybrack cave system make it arguably the most important underground karst site in Northern Ireland."
Carrickbeg Rising Cave (Bunty Pot)
Grid ref: H11724670. The rocks here date from the Quaternary, Carboniferous period and are designated PASSI. This cave is approximately 1 km long in a north–south direction and is divided into two parts. The main body of water flowing through the cave is traversable, but there is a 10 m flooded sump which emerges in another section known as the Farr Out Series.Carrickbeg Rising is the proven resurgence of four major stream sinks within the system: Pollnacrom, Polltullybrack, Waterfall Sink and Watson's Sink.
Fairy Cave
Grid ref: H09254750. The passages here date from the Holocene. The area has been designated a PASSI. Fairy Cave has been speculated to be part of a previous series of passages of the main Reyfad system. There is a small passage that runs along the joints of the bedrock and is only 1 m in height, which terminates in a sump; beyond this is a siltSilt
Silt is granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in a surface water body...
-choked hole.
Ivy Hole
Grid ref: H10694635. The rocks of this sinkhole are of Knockmore Limestone. The hole is designated a PASSI and is one of a pair of dolineDoline
Doline can refer to:* Doline , a village in the Kanjiža municipality, Serbia.* Sinkhole, a natural depression or hole in the surface topography caused by the removal of soil or bedrock, often both, by water....
s. A small stream flows into the sinkhole, which is estimated to be 10 m deep. It has been determined that the water from this hole emerges at Carrickbeg Rising.
Little Reyfad
Grid ref: H096465. The rocks of this sinkhole consist of Dartry Limestone, Knockmore Limestone and chert. The site has been designated a PASSI. Little Reyfad is at the base of a shakehole. A series of descents (7 m) leads to a floor of broken chert, followed by a further 3 metre difficult descent to another base, which is blocked with a rock and gravel.Mad Pot
Grid ref: H09444666. The rocks of this sinkhole are composed of Dartry Limestone and Knockmore Limestone with inclusions of chert. The sinkhole originates in peat and then cuts into limestone rock. There are a series of chert base levels which have been broken up in order to give access to further passages. When the substrata changes into Knockmore Limestone, the character of the cave changes to a more vertically oriented passage. After some more climbing there is a 22 m vertical drop with a further crawl at the base, which leads to a completely flooded section or sumpSump
A sump is a low space that collects any often-undesirable liquids such as water or chemicals. A sump can also be an infiltration basin used to manage surface runoff water and recharge underground aquifers....
, which itself is completely blocked up with silt. Above this is a very high roofed chamber or aven
Aven
Aven AVEN may refer to:* Asexual Visibility and Education Network, an Internet-based community to promote awareness of asexual orientation* Aven River in Brittany, France* Aven , a fictional bird race in Magic: The Gathering...
.
Murphy's Hole
Grid ref: H10054613. The rocks of this formation date from the Quaternary (Holocene) period and consist of limestone. The area is designated a PASSI.Murphy's Hole is situated at the north end of a depression that also contains Seltanacool Sinks. A waterfall drains into the sink, which takes a large volume of water in heavy rains. Water draining here has been dye traced
Dye tracing
Dye tracing is tracking and tracing various flows using dye added to the liquid in question. The purpose of tracking may be an analysis of the flow itself, of the transport of something by the flow of the objects that convey the flow...
to the resurgence at Carrickbeg.
Oweyglass Caves
Grid ref: H100470. The substrata from this formation dates from the Quaternary (Holocene) era and is composed of limestone. Designated a PASSI, it is situated in a cliff of Knockmore Limestone.This cave is linked to a series of springs. The longest passage here is reported to be no more than 15 m (49.2 ft).
Pollbeg
Grid ref: H11744557. The rocks from this sinkhole are of Carn and Dartry Limestones. The site is designated a PASSI. This hole floods in wet weather.Pollkeeran
Grid ref: H11834513. Also known as Pollkerran, this sinkhole is designated a PASSI. The strata consist of Carn Limestone with mudstoneMudstone
Mudstone is a fine grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.0625 mm with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey clay minerals may become aligned, with the...
and shale
Shale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...
deposits. This formation is thought to have been a cave roof, which has collapsed, normally known as a shakehole. The debris from the collapse has formed what is known as a 'choke hole'. Investigations have determined that the stream which sinks into Pollkeeran rises again 2 km to the north at Carrickbeg Rising Cave.
Extreme caution is advised as this sink is extremely dangerous and attempts to explore should only be undertaken by very experienced cavers.
Pollmore (Poll Mór)
Grid ref: H11654582. The rocks from this shakehole are of Carn Limestone. The shakehole contains two sinks and is surrounded by cliffs on three sides. In wet weather, the sinks flood and water up to 2 m deep can build up. It has been ascertained that the water from Pollmore emerges at Carrickbeg Rising.Pollnacrom
Grid ref: H08534702. The rocks from this formation are composed of Dartry and Knockmore Limestones with chert and gypsumGypsum
Gypsum is a very soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is found in alabaster, a decorative stone used in Ancient Egypt. It is the second softest mineral on the Mohs Hardness Scale...
. This site has been designated a PASSI.
This cave is part of the main Reyfad system that links to the 'Heaven and Hell' passage. It has a small, wet entrance. The cave contains two shafts at 50 and 15 m respectively, which permit entry to the main stream passage which trends in a north-west direction for 100 m (328.1 ft) before turning south. The cave has been explored for 600 m (1,968.5 ft) to an impassable sump. An attempt to force through this route in 1981 led to the death of a diver.
Access is by permission of landowner only.
Polltullybrack
Grid ref: H09214672. . The rocks in this second major entrance to the Reyfad system are composed of Dartry and Knockmore Limestones with chert and calcite formations. This cave is designated a PASSI.There is a very tight entrance to this cave through a sinkhole in what is known as a dry valley, but this eventually expands into a wider cave. The continuation of the passage contains many boulders and a deep pool, followed by 250 m of difficult passage which ends in a submerged section, through which cavers have to duck. A short distance beyond this there is a 53-metre shaft, which is the longest-known pitch
Pitch (vertical space)
-Climbing:In rock climbing and ice climbing, a pitch is a steep section of a route that requires a rope between two belays, as part of a climbing system...
of any Irish cave. The cave joins up with the Reyfad system just north of the main chamber. Just before this are chambers known as the 'Grottoes', which contain fine examples of calcite features including stalactite
Stalactite
A stalactite , "to drip", and meaning "that which drips") is a type of speleothem that hangs from the ceiling of limestone caves. It is a type of dripstone...
s, helictite
Helictite
A helictite is a speleothem found in limestone caves that changes its axis from the vertical at one or more stages during its growth. They have a curving or angular form that looks as if they were grown in zero gravity...
s and cave curtains.
Access is by permission of landowner only.
Rattle Hole
Grid ref: H10234633. The rocks from this pothole are limestone with some gravelGravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...
. The site, located in moorland, has been designated a PASSI.
Rattle Hole consists of a single shaft of 36 m (118.1 ft) depth, which terminates in a boulder strewn base. This provides access to a second chamber, which is a further 25 m (82 ft) deep and ends in a gravel base. Further efforts at extending this passage have proved fruitless, but as a result of dye testing it is known that the water from here emerges at Carrickbeg.
Reyfad Pot (Pota Raith Fada)
Grid ref: H08894687. The rocks from this formation comprise Carn and Dartry Limestones with some Glenade SandstoneSandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
. Breccia
Breccia
Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....
, chert, calcite and gypsum deposits can also be found.
This cave is noted by the Northern Ireland Environment Agency as being the most important underground karst site in Northern Ireland. At 193 metres (633.2 ft) deep and 6.7 kilometres (4.2 mi) long, it is the deepest cave system in Ireland and the second-longest in Northern Ireland. This site is a PASSI and is a very active cave with many calcite formations and fossiliferous limestone, which includes evidence of Brachiopods and Crinoid
Crinoid
Crinoids are marine animals that make up the class Crinoidea of the echinoderms . Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 meters. Sea lilies refer to the crinoids which, in their adult form, are...
s. The extended area is hypothesised to have formed from the last glacial period (Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
).
Access is by permission of landowner only.
Seltanacool Sinks
Grid ref: H102458. . The rocks from this line of three sinks date from the Quaternary (Holocene) and consist of limestone. It is thought that the sinks, which are situated in the same depression as Murphy's Hole, link to Carrickbeg Rising.Arch Cave
Grid ref: H1037 4790. This cave is also known as Ooghboraghan. The rocks comprise Dartry Limestone, Glenade Sandstone, Glencar Limestone, Knockmore Limestone, Meenymore Formation. These are found together with breccia, chert, limestone, mudstone and calcite.Aughakeeran Pot
Grid ref: H09344765. Also known as Pollaphylla or Pollasod, the rocks of this potholePothole
A pothole is a type of disruption in the surface of a roadway where a portion of the road material has broken away, leaving a hole.- Formation :...
comprise Dartry and Knockmore Limestones. The site is designated a PASSI.
This sinkhole contains a substantial shaft of 30 m (98.4 ft) depth, with some crawling sections and short passages which ultimately end at an impenetrable crack in the rocks. The stream passing through Aughakeeran is believed to join the drainage through Pollanaffrin.
Crunthelagh Sink
Grid ref: H09374793. The rocks from this sinkhole comprise Dartry and Knockmore Limestones. The formation is designated a PASSI. The water flowing into this sink is thought to emerge into 'High Noon's' in the Noon's–Arch system.Lettered Cave (Inscribed Cave)
Grid ref H08845047. Situated 50 m from Knockmore summit, this is a small cave of mainly archaeological significance, and is partially man-made. The rocks in which it is formed is Knockmore Limestone.The cave is named for the art and writing of varying age inscribed on the walls. It was investigated by William Wakeman (1866–70) and Thomas Plunkett (1878 and 1898) and is now a scheduled ancient monument.
Old Barr Sink
Grid ref H09244844. The rocks from this formation comprise Dartry Limestone and Knockmore Limestone. The feature is designated as a PASSI.This sink is found in a forested area containing a small stream, which sinks in several places. The water from the stream is believed to enter 'Inlet 1' beside 'Artie's Chamber' in the Noon's–Arch system.
Pollanaffrin
Grid ref: H09354754. The rocks from this sinkhole comprise Dartry Limestone and Knockmore Limestone. The area is designated a PASSI.A large river enters this pot hole when there is much rain. The cave follows many twists and drops and is of considerable length before it terminates at an impasse. It has been speculated that the water from this system enters Noon's Hole.