Llyn y Fan Fawr Llyn y Fan Fawr Llyn y Fan Fawr (Welsh: 'lake of the big peak') is a natural lake in the county of Powys, Wales. It lies at the foot of Fan Brycheiniog, the highest peak of the Black Mountain (Welsh"Y Mynydd Du") range within the Brecon Beacons National Park. Created as a result of glacial action, it is one of the largest glacial lakes in southern Wales. The lake is roughly rectangular in shape with its long axis oriented roughly north-south. The surface of Llyn y Fan Fawr lies at about 1815 feet or 605m above sea level. Its primary
Pen Llithrig y Wrach underfoot, or because of the resemblance of its pointed profile to an archetypal witch's hat. It is an outlier of the Carneddau, the higher peaks of which can be reached from Pen Llithrig y Wrach via Pen yr Helgi Du. On its eastern side, the mountain slopes steeply down to Llyn Cowlyd. It may be climbed from the southern side, from Capel Curig or the A5, or from the north-east, from Dolgarrog or Tal-y-bont in the Conwy valley. It is quite prominent when viewed from the north near Llandudno. Pen Llithrig y Wrach Pen Llithrig y Wrach is a mountain