ESCR - Outlying Sites in Fermanagh & Tyrone; Knockninny & Molly Mountain

Earth Science Conservation Review

Summary Full report
Outlying Sites in Fermanagh & Tyrone; Knockninny & Molly Mountain	Fermanagh

Site number:	1166
ESCC:	IC
Locality Type:	Karst	Status:	ASSI
Grid Reference:	H273300,H240287 Centroid, Not Entered
Google maps:	54.21867,-7.58148
County:	Fermanagh	Council area:	Fermanagh & Omagh District Council
Period:	Quaternary, Carboniferous
Stages:	Asbian, Holocene, Visean
Lithostrat:	Dartry Limestone Formation, Glenade Sandstone Formation, Knockmore Limestone Member, Meenymore Formation

Site Description
Description:
ESCRIPTION &
Importance:
Neither Knockninny nor Molly Mountain are of significant speleological or karst geomorphological interest.
Interpretation:
The Knockninny relict cave is a 10m passage with an entrance at each end at the base of the small cliffs on the west slopes of Knockninny Hill. It is of little speleological value. A cave was reported to have been exposed by quarrying in Knockninny Quarry but was then destroyed. There are three swallow holes marked on the 1:25,000 O.S. Upper Lough Erne sheet on the northwestern flanks of Molly Mountain in the townlands of Molly and Glasdrumman. The most northerly site is a stream sink below a small 5m cliff. The strata dip steeply to the southwest and the limestone is the Cherty facies of the Dartry Limestone. There is an exposure of a Tertiary intrusion in the small waterfall at the entrance to the swallow hole. The other two sites to the south have small amounts of water sinking into them and all three sites are situated on a limestone bench between 170m and 200m amsl.
Conclusions:
CONCLUSION The sites are not of significant interest to warrant ASSI designation.
Notes:
For site specific information see; Key Site 432 - Knockninny relict cave Key Site 433 - Molly Stream Sink. For information and reference lists on the systems and features of other outlying karst areas in Fermanagh and Tyrone see; Key Site 1163 - Garrison Key Site 1164 - Fardrum Key Site 1165 - Kiltierney Deer Park Key Site 1167 - Lough Lee-Binnawooda area Key Site 1168 - Slieve Beagh area. BIOLOGICAL INTEREST There is no biospeleological interest in this area.

Keywords
Rocks:	Limestone
Geomorph:	cave, doline, sinkhole

Access
Planning:	HISTORY OF EXPLORATION Both sites are recorded in Jones (1974) and in 1875 Plunkett (Coleman 1965) dug a small passage in Knockninny and recovered some human remains and other artifacts. There are no other known records of karst interest for these sites.

References (27)
Adair, F., 1974. Notes on the distribution and behaviour of the cave spider, Meta menardi (Latr.) in Ireland (Araneae Argiopidae). Irish Naturalists Journal, vol. 18 pt. 2, pp.40-41.
Barnes, S., 1994. Preliminary Hydrological Investigation of the Area between Carnlough and Waterfoot, County Antrim, Northern Ireland. (Thesis) University of East Anglia.
Boon, M., 1977. Down to a Sunless Sea.
Brook, D., 1971. Notes on the Reyfad Area. University of Leeds Speleological Association Review, numb. 8.
Clark, S., 1975. Hull University Speleological Society Expedition to Northern Ireland 1975. Hull University Speleological Society.
Coleman, J., 1965. The Caves of Ireland. Anvil Books, Tralee.
Drew, D.et al., 1977. Caves and Karsts of Ireland. In 7th International Speleological Congress British Cave Research Association.
Fletcher, T.P., 1977. Lithostratigraphy of the Chalk (Ulster White Limestone Formation) in Northern Ireland. Report of the Institute of Geological Sciences, vol. 77/14.
Gunn, J., 1985. Water Tracing in the North Cuilcagh Karst. Irish Speleology, vol. 3 pt. 2.
Halliwell, R.A., 1970. An Elementary Study of the Cave Morphology and Seepage in the Reyfad-Pollnacrom System. Transactions of the Cave Research Group of Great Britain, vol. 12 numb. 4.
Hazleton, M., 1973. Irish Hypogean Fauna and Irish Biological Records 1856-1971. Transactions of the Cave Research Group of Great Britain, vol. 15 numb. 4.
Hopkirk, A., 1994. The Search for Bat Hibernacula in Ireland. The Leisler. Magazine of the Northern Ireland Bat Group, vol. 1994 numb. Spring.
Jameson, H.L., 1896. On the Exploration of the Caves of Enniskillen and Mitchelstown for the R.I.A. Flora and Fauna Committee. Irish Naturalists Journal, vol. 5, pp.93-100, plates 1.
Jones, G.Ll. & McKeever, M., 1987. Sediments and Palynology in Marble Arch Cave. Cave Science, vol. 14 numb. 1.
Kelly, J.G., 1989a. The late Chadian to Brigantian Geology of the Carrick-on-Shannon and Lough Allen Basins, North West Ireland. (Thesis) N.U.I.
Kelly, J.G., 1989b. Geology and Caves of Cuilcagh Mountain, Counties Fermanagh and Cavan. Irish Speleology, vol. 13.
Kelly, J.G., 1990. Reyfad Pot. Irelands Deepest (and Longest?) Descent 96.
Kelly, J.G., 1995. The Asbian Geology of Cuilcagh Mountain Area, Co's Fermanagh and Cavan, Ireland. Initiation, growth and decline of a tectonically controlled carbonate ramp. In European Dinantian Environments II.
Legg, I.C., Johnston, T.P., Mitchell, W.I. & Smith, R.A., 1995. Geology of the country around Derrygonelly and Marble Arch. Memoirs of the Geological Survey Northern Ireland, vol. Sheet 44,56,43.
Magennis, P., 1874. The Ribbon Informer. A Tale of Lough Erne. Frederick Bell and Co.
Martel, E.A., 1897. Irelande et Cavernes Anglaises. Libraire ch. Delagrave., Paris.
McKay, S., 1987. The Chemical Differentiation of Carbonate Aquifers in the Karst of North-West Ireland, with a view to predicting the type and length of cave system under Belmore Mountain. (Thesis) University of Bristol.
McKay, S., 1989. A study of Carbonate Aquifers in the Karst of North West Ireland. Irish Speleology, vol. 13.
Nichols, A., 1970. Cambridge University Caving Club Expedition to Ireland, 1970. Cambridge University Caving Club.
Oswald, D.H., 1955. The Carboniferous Rocks between the Ox Mountains and Donegal Bay. Journal of the Geological Society of London, vol. 111, pp.167-186.
Sheridan, D.J.R., 1972. Upper Old Red Sandstone and Lower Carboniferous of the Slieve Beagh Syncline and its setting in the northwest Carboniferous basin, Ireland. Special Papers of the Geological Survey of Ireland, vol. 2, pp.1-120.
Williams, P.W., 1970. Limestone morphology in Ireland. In Irish Geographical Studies, pp.105-124 Queens University of Belfast.

Map(s):	See the 1:50,000 O.S. Sheet 27 (Upper Lough Erne).
Record type:	ESCR report
Entered by:	E M Porter

Enlander, I., Dempster, M. & Doughty, P., 2026. Outlying Sites in Fermanagh & Tyrone; Knockninny & Molly Mountain, County Fermanagh, site details. [In] Earth Science Conservation Review.
https://www.habitas.org.uk/escr/site.php?item=1166. Accessed on 2026-11-08.