Waun Fach is, with a summit height of , the highest

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited Summit (topography), summit area, and ...

in the Black Mountains in south-eastern

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 ...

. It is one of the three Marilyns over 600 m that make up the range, the others being Black Mountain and

Mynydd Troed Mynydd Troed is a hill in the Black Mountains of the Brecon Beacons National Park in Powys, south Wales. Its name literally translates to "Foot Mountain," based how it appears when viewed from the Allt Mawr ridge. It lies south of Talgart ...

. To the north Rhos Fawr and the

Radnor Forest Radnor Forest ( cy, Fforest Clud) in the county of Radnorshire, Wales is a rock dome composed of Silurian shales, mudstones and limestone in Mid Wales. It is a forest in the medieval sense of the word (an area of land set aside for hunting). I ...

can be seen. It is the third highest mountain in Britain south of

Snowdonia Snowdonia or Eryri (), is a mountainous region in northwestern Wales and a national park of in area. It was the first to be designated of the three national parks in Wales, in 1951. Name and extent It was a commonly held belief that the nam ...

(after

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 its near neighbour

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 situated at the head of the Grwyne Fechan valley, above and to the west of the

Grwyne Fawr The Grwyne Fawr is a river in the Brecon Beacons National Park in south Wales. A section of it forms the administrative border between Powys and Monmouthshire and also of the historic counties of Brecon and Monmouth. The river and its major tri ...

reservoir. It has an undistinguished (and almost indistinguishable) rounded summit. The nearby tops on the ridge, Pen Trumau and

Pen y Gadair Fawr Pen y Gadair Fawr is an high subsidiary summit of Waun Fach and the second highest peak in the Black Mountains in south-eastern Wales. Marked by a medium-sized cairn, it is a much more distinguished top than its parent 1.5 km to the no ...

, although lower, are very much more recognisable.

Geology

The summit and upper slopes of Waun Fach are formed from the Early Devonian Epoch

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, a division 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 ...

. Beneath these and forming the lower slopes are the sandstones of the Senni Formation (traditionally the Senni Beds).

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. ...

layers within these sandstones are more readily eroded and have given rise to the stepped appearance of parts of the mountain. No rocks are exposed around its summit as this is covered by a thick layer of

peat Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficien ...

which has accumulated in the postglacial period, though is much reduced through erosion in recent decades.

Access

The hill is wholly within land mapped under the

Countryside and Rights of Way Act 2000 The Countryside and Rights of Way Act 2000 (c. 37), known informally as the CRoW Act or "Right to Roam" Act is a United Kingdom Act of Parliament affecting England and Wales which came into force on 30 November 2000. Right to roam The Act imp ...

as open country and hence is legally available to walkers despite there being no public rights of way leading to it. Mountain bikers and horseriders can follow the

bridleway A bridle path, also bridleway, equestrian trail, horse riding path, ride, bridle road, or horse trail, is a trail or a thoroughfare that is used by people riding horses, riding on horses. Trails originally created for use by horses often now s ...

s which lead to the 617m high col south of Pen Trumau but have no legal access to the hill itself. The paths approaching from the north and west have been repaired and improved by the

Brecon Beacons National Park Authority 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 ...

, most recently through the Black Mountains Land Use Partnership in recent years, having previously become particularly damaged by use.

References

External links

* Computer generated summit panoramas: *
Waun Fach
*

*
www.geograph.co.uk : photos of Waun Fach and surrounding area
{{British hills Marilyns of Wales Hewitts of Wales Nuttalls Landmarks in Wales Mountains and hills of Powys Black Mountains, Wales Talgarth