Llyn Cwm Llwch

Llyn Cwm Llwch is a lake in the Brecon Beacons National Park in Powys, Wales. It is a small lake of glacial origin occupying a rock hollow beneath the peaks of Pen y Fan and Corn Du in the central Brecon Beacons. It is drained by the Nant Cwm Llwch which empties into the Afon Tarell which itself enters the River Usk at Brecon. Tommy Jones' obelisk, a memorial in granite to a young boy who died near this spot many years ago, overlooks the lake. The lake occupies a hollow excavated in the sandstones of the Brownstones Formation of the Old Red Sandstone by glacial action during the succession of recent ice ages. Its northern margins are rimmed by an arcuate late-glacial moraine. The lake is within open country and readily accessible to...