Llyn y Fan Fawr outflow is to the River Tawe. Much of the land around the lake is peaty and thus wet underfoot. 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.
Pen y Gaer Pen y Gaer Pen y Gaer (or Pen-y-gaer) is the location of a Bronze Age and Iron Age hillfort near the village of Llanbedr-y-Cennin in the Conwy valley, Wales. A natural defensive site, it had a long history of occupation, indicated by the complexity of the defences, which were amended over time. There are two Bronze Age cairns on the north-west slope, and extensive prehistoric and later field systemsare nearby. The remains as seen today are mostly of Iron Age origin, but further earthworks, probably of medieval origin, lie on the south-eastern slopes. The remains of the two walls of