Cribyn is a mountain in the

Brecon Beacons The Brecon Beacons ( cy, Bannau Brycheiniog, ) are a mountain range in South Wales. In a narrow sense, the name refers to the range of Old Red Sandstone peaks which lie to the south of Brecon. Sometimes referred to as "the central Beacons" t ...

with an elevation of 2608 feet (or 795 metres) about 300 feet lower than the neighbouring peaks of

Pen y Fan Pen y Fan () is the highest peak in South Wales, situated in the Brecon Beacons National Park. At above sea-level, it is also the highest British peak south of Cadair Idris in Snowdonia. It is the highest point (county top) of the historic cou ...

and

Corn Du Corn Du is a summit of the twin topped Pen y Fan and the second highest peak in South Wales at 873 m (2,864 ft), situated in the Brecon Beacons National Park. The summit itself is marked by a well structured Bronze Age cairn with a cen ...

. It is a prominent peak in the long and impressive

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 ...

facing north and running roughly east–west of the central section of the Brecon Beacons. The summit lies on a ridge stretching from

Talybont Reservoir Talybont Reservoir ( cy, Cronfa Ddŵr Tal-y-bont) is the largest stillwater reservoir in the central Brecon Beacons at . Talybont-on-Usk is downstream of the dam. Construction of the current dam started in 1931 by Newport Corporation, and in ...

in the east, to the

A470 road The A470 (also named the Cardiff to Glan Conwy Trunk Road) is a trunk road in Wales. It is the country's longest road at and links the capital Cardiff on the south coast to Llandudno on the north coast. While previously one had to navigate t ...

. The ridge line to the west connects Cribyn with the peak of

. To the east, the ridge line descends to Bwlch ar y Fan, a col crossed by an ancient trail sometimes known as 'The Gap Road' before ascending again to the peak of

Fan y Big Fan y Big (Welsh: ) is a subsidiary summit of Waun Rydd in the Brecon Beacons National Park, in southern Powys, Wales. It is high and is often hiked as part of the Horseshoe Walk, a traverse of the four main peaks in the Brecon Beacons. The hil ...

br>
https://books.google.com/books?id=ROPTbj9als4C&pg=PA19&lpg=PA19&dq=fan+y+big+the+gap&source=web&ots=FUpLQfSmib&sig=XndaQqqTFH7dYopBTBgGSMaQtcM&hl=en]

Geology

Cribyn and the top of Cwm Sere - geograph

In common with other peaks of the Brecon Beacons, the upper slopes of Cribyn are formed from

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

s of the Brownstones Formation of the

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 ...

laid down during the

Devonian period The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, wh ...

. The lower slopes of the hill are formed from sandstones and

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology. ...

s of the underlying Senni Beds Formation. The

rock strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ei ...

tilt gently southward like the rest of the peaks in the range. The heads of Cwm Sere and Cwm Cynwyn, to the northwest and east of Cribyn respectively, nurtured small glaciers during the last

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...

and there are rock

moraine A moraine is any accumulation of unconsolidated debris (regolith and rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice shee ...

s at the foot of the cliffs. The

glacial erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

resulted in the very steep northern and eastern faces which the hill possesses.

Access

Cribyn seen from Cefn Cwm Llwch - geograph

The

are classed as

open country "Open Country" is a designation used for some UK access land. It was first defined under the National Parks and Access to the Countryside Act 1949 (and extended by the Countryside Act 1968), and was land over which an appropriate access agreeme ...

, so the visitor can walk anywhere in the highland zone. Trails and footpaths are well marked, and owing to frequent use, are also well trodden. The

National Trust The National Trust, formally the National Trust for Places of Historic Interest or Natural Beauty, is a charity and membership organisation for heritage conservation in England, Wales and Northern Ireland. In Scotland, there is a separate and ...

owns much of the land and the paths are well maintained and reinforced where wear and tear is heavy. The main paths are intensively used by individual walkers and groups, but also by the

British Army The British Army is the principal land warfare force of the United Kingdom, a part of the British Armed Forces along with the Royal Navy and the Royal Air Force. , the British Army comprises 79,380 regular full-time personnel, 4,090 Gurk ...

for troop training, and by charity walks. The peak is adjacent to

so is often chosen for circular walks along the main

. When the weather is clear, the views to the north are especially impressive towards

Mynydd Epynt Mynydd Epynt () is a former community and upland area in Powys, Wales. The Ministry of Defence controversially evicted the community of Mynydd Epynt in 1940, creating what is now the core of the Sennybridge Training Area (SENTA), the largest mil ...

Brecon Brecon (; cy, Aberhonddu; ), archaically known as Brecknock, is a market town in Powys, mid Wales. In 1841, it had a population of 5,701. The population in 2001 was 7,901, increasing to 8,250 at the 2011 census. Historically it was the coun ...

and the

Cambrian Mountains The Cambrian Mountains ( cy, Mynyddoedd Cambria, in a narrower sense: ''Elenydd'') are a series of mountain ranges in Wales. The term ''Cambrian Mountains'' used to apply to most of the upland of Wales. Since the 1950s, its application has becom ...

beyond.

Wildlife

Falco peregrinus -Morro Rock, Morro Bay, California, USA -flying-8

Many mountain birds are present, such as

birds of prey Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predators ...

peregrine falcon The peregrine falcon (''Falco peregrinus''), also known as the peregrine, and historically as the duck hawk in North America, is a Cosmopolitan distribution, cosmopolitan bird of prey (Bird of prey, raptor) in the family (biology), family Falco ...

common buzzard The common buzzard (''Buteo buteo'') is a medium-to-large bird of prey which has a large range. A member of the genus ''Buteo'', it is a member of the family Accipitridae. The species lives in most of Europe and extends its breeding range across ...

s and the

red kite The red kite (''Milvus milvus'') is a medium-large bird of prey in the family Accipitridae, which also includes many other diurnal raptors such as eagles, buzzards, and harriers. The species currently breeds in the Western Palearctic region o ...

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 assigned t ...

s can also be seen occasionally, and more often heard by their deep croak. They use

thermals A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...

in the valleys around the peaks to soar and search for food such as

mice A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

and

vole Voles are small rodents that are relatives of lemmings and hamsters, but with a stouter body; a longer, hairy tail; a slightly rounder head; smaller eyes and ears; and differently formed molars (high-crowned with angular cusps instead of low-c ...

s. The lower parts of the

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 ...

adjacent to the peaks is used for nesting by

skylark ''Alauda'' is a genus of larks found across much of Europe, Asia and in the mountains of north Africa, and one of the species (the Raso lark) endemic to the islet of Raso in the Cape Verde Islands. Further, at least two additional species are ...

s as well as some

game bird Galliformes is an order of heavy-bodied ground-feeding birds that includes turkeys, chickens, quail, and other landfowl. Gallinaceous birds, as they are called, are important in their ecosystems as seed dispersers and predators, and are often ...

s like

red grouse The red grouse (''Lagopus lagopus scotica'') is a medium-sized bird of the grouse family which is found in heather moorland in Great Britain and Ireland. It is usually classified as a subspecies of the willow ptarmigan but is sometimes consider ...

and

partridges A partridge is a medium-sized galliform bird in any of several genera, with a wide native distribution throughout parts of Europe, Asia and Africa. Several species have been introduced to the Americas. They are sometimes grouped in the Perdic ...

. The skylark can frequently be seen soaring and heard singing above its nest.

References

External links

{{Commons category, Cribyn (mountain), Cribyn
www.geograph.co.uk : photos of Cribyn and surrounding area
Brecon Beacons Mountains and hills of Powys Hewitts of Wales Nuttalls