Cribyn is a mountain in the Brecon Beacons 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 c ...

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 c ...

. 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 ''esca ...

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 ...

. 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 Bigbr>
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, w ...

. The lower slopes of the hill are formed from sandstones and mudstones of the underlying Senni Beds Formation. The rock strata 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 gre ...

and there are rock moraines at the foot of the cliffs. The

glacial erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust, and then sediment transport, tra ...

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

Access

Cribyn seen from Cefn Cwm Llwch - geograph

The Brecon Beacons 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 agree ...

, 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 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 predat ...

like peregrine falcons, common buzzards 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 ...

. Ravens 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 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 lo ...

s. The lower parts of the moorland 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 ofte ...

s like red grouse 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