Fan Fraith is a top of

Fan Gyhirych Fan Gyhirych is a mountain in the Fforest Fawr section of Brecon Beacons National Park in south Wales. It lies within the county of Breconshire, and administered as part of the unitary authority of Powys. Its highest point at 2379 feet (or ...

in the

Fforest Fawr Fforest Fawr is an extensive upland area in the county of Powys, Wales. Formerly known as the Great Forest of Brecknock in English, it was a royal hunting area for several centuries but is now used primarily for sheep grazing, forestry, water cat ...

section of 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) in ...

in the county of

Powys Powys (; ) is a Local government in Wales#Principal areas, county and Preserved counties of Wales, preserved county in Wales. It is named after the Kingdom of Powys which was a Welsh succession of states, successor state, petty kingdom and princi ...

, south

Wales Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the ...

. Its summit is at a height of 2192 feet or 668 m. It lies within

Fforest Fawr Geopark Fforest Fawr Geopark is a Geopark in the Brecon Beacons National Park, south Wales. It is the first designated Geopark in Wales having gained membership of both the European Geoparks Network and the UNESCO-assisted Global Network of National Ge ...

Geology

The bulk of the hill is 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 and mudstones 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 ext ...

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, whe ...

. Sandstones of the overlying Plateau Beds Formation occur in the summit area as do beds of the Grey Grits Formation - both are assigned to the upper Devonian. The Plateau Beds sandstones occur across the whole southern aspect of the mountain and are often present as boulder fields,a result of

periglacial Periglaciation (adjective: "periglacial", also referring to places at the edges of glacial areas) describes geomorphic processes that result from seasonal thawing of snow in areas of permafrost, the runoff from which refreezes in ice wedges and ...

activity. Several geological faults affect these rocks, the most significant of which is the northeast-southwest aligned Swansea Fault, a part of the

Cribarth Disturbance The Cribarth Disturbance is a geological structure forming a lineament which stretches across south Wales from Swansea up the Swansea Valley then northeastwards to Brecon and beyond. It consists of both a series of faults and associated folds w ...

.British Geological Survey 1:50,000 map sheet 231 'Merthyr Tydfil' & accompanying memoir

Access

The hill is entirely within access land and freely available to walkers. A private vehicular track which runs over the southeastern shoulder of neighbouring

affords the easiest and most commonly used ascent of Fan Fraith.

References

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External links

images of Fan Fraith & surrounding area on Geograph website
Mountains and hills of Powys Fforest Fawr Nuttalls