Craig y Cilau is a

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms when ...

escarpment An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations. The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''escar ...

in the

Brecon Beacons National Park The Brecon Beacons National Park ( cy, Parc Cenedlaethol Bannau Brycheiniog) is one of three national parks in Wales, and is centred on the Brecon Beacons range of hills in southern Wales. It includes the Black Mountain ( cy, Y Mynydd Du) i ...

Powys Powys (; ) is a county and preserved county in Wales. It is named after the Kingdom of Powys which was a Welsh successor state, petty kingdom and principality that emerged during the Middle Ages following the end of Roman rule in Britain. Geogr ...

Wales Wales ( cy, Cymru ) is a country that is part of the United Kingdom. It is bordered by England to the east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in 202 ...

. It was declared a national nature reserve in 1959 because of its importance for wildlife, particularly plants. It is situated on the north side of Mynydd Llangatwg in Llangattock

community A community is a social unit (a group of living things) with commonality such as place, norms, religion, values, customs, or identity. Communities may share a sense of place situated in a given geographical area (e.g. a country, village, ...

, about south-west of Crickhowell. The reserve covers and has a varied geology with

Old Red Sandstone The Old Red Sandstone is an assemblage of rocks in the North Atlantic region largely of Devonian age. It extends in the east across Great Britain, Ireland and Norway, and in the west along the northeastern seaboard of North America. It also exte ...

below the cliffs and Millstone Grit above them. The range of habitats is equally wide with

woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...

and scrub in the lower parts and

moorland Moorland or moor is a type of habitat found in upland areas in temperate grasslands, savannas, and shrublands and montane grasslands and shrublands biomes, characterised by low-growing vegetation on acidic soils. Moorland, nowadays, generally ...

higher up. There are numerous

cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea c ...

s and disused

quarries A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their enviro ...

along the escarpment. The limestone cliffs are home to many scarce plants including maiden pink (''Dianthus deltoides''), hutchinsia ('' Hornungia petraea'') and the most southerly British population of alpine enchanter's nightshade ('' Circaea alpina''). Five species of

whitebeam The whitebeams are members of the family Rosaceae, comprising subgenus ''Aria'' (or, according to some authorities, its own genus) of genus ''Sorbus'', and hybrids involving species of this subgenus and members of subgenera ''Sorbus'', ''Torminar ...

occur including the narrow-leaved whitebeam (''Sorbus leptophylla'') and lesser whitebeam (''Sorbus minima'') which are

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to Wales. About 50 species of bird breed on the reserve including ring ouzel and

raven A raven is any of several larger-bodied bird species of the genus ''Corvus''. These species do not form a single taxonomic group within the genus. There is no consistent distinction between " crows" and "ravens", common names which are assigne ...

on the cliffs and

redstart {{Hatnote, For the ship, see USS Redstart (AM-378) Redstart is a name used for a number of songbird A songbird is a bird belonging to the suborder Passeri of the perching birds ( Passeriformes). Another name that is sometimes seen as the scie ...

wood warbler The wood warbler (''Phylloscopus sibilatrix'') is a common and widespread leaf warbler which breeds throughout northern and temperate Europe, and just into the extreme west of Asian Russia in the southern Ural Mountains. This warbler is str ...

and pied flycatcher in the woods. One of the caves, Agen Allwedd, holds a roost of lesser horseshoe bats during the winter months.

References

*Condry, William M. (1990) ''The Natural History of Wales'', Bloomsbury Books, London. *Saunders, David (1974) ''A guide to the birds of Wales'', Constable, London.
Visit Mid Wales: Craig y Cilau
Accessed 3 March 2008.

External links

Photos of Craig y Cilau and surrounding area on geograph
National nature reserves in Wales Mountains and hills of Powys Brecon Beacons {{powys-geo-stub