Picws Du

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. Picws Du is formed from the sandstones and mudstones of the Brownstones Formation of the Old Red Sandstone 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...