Picws Du
Encyclopedia
Picws Du is the highest peak of the Carmarthen Fans or Bannau Sir Gaer in the Carmarthenshire
section of the Black Mountain
in the west of the Brecon Beacons National Park in south Wales
. It is a subsidiary summit of Fan Brycheiniog
.
It is within Fforest Fawr Geopark
. Its prominent summit is marked by an ancient cairn at a height of 749m above sea level. Waun Lefrith
is the other, lower summit of the Bannau Sir Gaer / Carmarthen Fans.
laid down during the Devonian period. Its summit and southern slopes are formed from the hard-wearing sandstones of the overlying Plateau Beds Formation which are of upper/late Devonian age. The northwestern and northeast faces of Picws Du were home to small glaciers during the ice ages which gouged out the cwm
s of Pwll yr Henllyn and Pant y Bwlch. These cwms drain via the Afon Sawdde into the River Towy. The southern slopes drain into the Afon Twrch
and so into the River Tawe
.
and Fan Foel. The high level route of the Beacons Way from Llangadog
to Abergavenny
runs over Picws Du whilst the low level route runs up to Llyn y Fan Fach
and beside the Afon Sychlwch at the foot of its northern escarpment.
Carmarthenshire
Carmarthenshire is a unitary authority in the south west of Wales and one of thirteen historic counties. It is the 3rd largest in Wales. Its three largest towns are Llanelli, Carmarthen and Ammanford...
section of the Black Mountain
Black Mountain (range)
The Black Mountain is a mountain range in Mid and West Wales, straddling the county boundary between Carmarthenshire and Powys and forming the westernmost range of the Brecon Beacons National Park. Its highest point is Fan Brycheiniog at 802 metres or 2,631 ft. The Black Mountain also forms a part...
in the west of the Brecon Beacons National Park in south Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
. It is a subsidiary summit of Fan Brycheiniog
Fan Brycheiniog
Fan Brycheiniog is the highest peak in the Black Mountain region of the Brecon Beacons National Park in South Wales. It is just inside the county of Powys, and also within the Fforest Fawr Geopark designated in 2005 in recognition of the area's geological heritage.The Beacons Way, a waymarked long...
.
It is within Fforest Fawr Geopark
Fforest Fawr Geopark
Fforest Fawr Geopark was the first Geopark to be designated in Wales having gained membership of both the European Geoparks Network and the UNESCO-assisted Global Network of National Geoparks in October 2005. The Geopark aims to promote and support sustainable tourism and other opportunities to...
. Its prominent summit is marked by an ancient cairn at a height of 749m above sea level. Waun Lefrith
Waun Lefrith
Waun Lefrith is a top of Picws Du and is also the westernmost of the Carmarthen Fans or Bannau Sir Gaer, a group of peaks within the Black Mountain of the Brecon Beacons National Park. It lies within the county of Carmarthenshire. The summit plateau of the mountain reaches a height of 677m above...
is the other, lower summit of the Bannau Sir Gaer / Carmarthen Fans.
Geology
Picws Du is formed from the sandstones and mudstones of the Brownstones Formation of the Old Red SandstoneOld Red Sandstone
The Old Red Sandstone is a British rock formation of considerable importance to early paleontology. For convenience the short version of the term, 'ORS' is often used in literature on the subject.-Sedimentology:...
laid down during the Devonian period. Its summit and southern slopes are formed from the hard-wearing sandstones of the overlying Plateau Beds Formation which are of upper/late Devonian age. The northwestern and northeast faces of Picws Du were home to small glaciers during the ice ages which gouged out the cwm
Cwm
cwm may refer to* the geographical term for a rounded, glaciated valley also known as a corrie or cirque* the Welsh word for a valley, sometimes anglicized to Coombe* cwm , a general-purpose data processor for the semantic web...
s of Pwll yr Henllyn and Pant y Bwlch. These cwms drain via the Afon Sawdde into the River Towy. The southern slopes drain into the Afon Twrch
Afon Twrch
The Afon Twrch is a river which rises in the Black Mountain in south Wales. It forms the boundary between the counties of Powys and Carmarthenshire and, downstream of Ystradowen, between Powys and Neath Port Talbot county borough.The headwaters arise on the southern slopes of Bannau Sir Gaer and...
and so into the River Tawe
River Tawe
The River Tawe is a river in South Wales. It flows in a principally south-westerly direction for some from its source below Moel Feity in the Old Red Sandstone hills of the western Brecon Beacons to the Bristol Channel at Swansea. Its main tributaries are the right bank Upper and Lower Clydach...
.
Access
The entire mountain is open country and so freely accessible to walkers. The most popular approach includes a circuit of the neighbouring peaks of Waun LefrithWaun Lefrith
Waun Lefrith is a top of Picws Du and is also the westernmost of the Carmarthen Fans or Bannau Sir Gaer, a group of peaks within the Black Mountain of the Brecon Beacons National Park. It lies within the county of Carmarthenshire. The summit plateau of the mountain reaches a height of 677m above...
and Fan Foel. The high level route of the Beacons Way from Llangadog
Llangadog
Llangadog is a community located in Carmarthenshire, Wales, which includes the villages of Llangadog, Bethlehem and Capel Gwynfe. A notable local landscape feature is Y Garn Goch with two Iron Age hill forts....
to Abergavenny
Abergavenny
Abergavenny , meaning Mouth of the River Gavenny, is a market town in Monmouthshire, Wales. It is located 15 miles west of Monmouth on the A40 and A465 roads, 6 miles from the English border. Originally the site of a Roman fort, Gobannium, it became a medieval walled town within the Welsh Marches...
runs over Picws Du whilst the low level route runs up to Llyn y Fan Fach
Llyn y Fan Fach
Llyn y Fan Fach is a dammed lake in the eastern border of the Black Mountain in Carmarthenshire, south Wales. Near to it is found Llyn y Fan Fawr.-Legend of Llyn y Fan Fach:...
and beside the Afon Sychlwch at the foot of its northern escarpment.