A natural lake covering over 3 hectares on the west facing slopes of Pant y Llyn. It has been dammed at its western and northeastern ends to create local water supplies, NPRNs 247274 and 247275. In the late 19th century a boat house, NPRN 247009, was shown on the southern side of the lake. J.J. Hall, Trysor, 19 February 2009.