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 Fan Corn Du. It takes its name from a large coaching inn with a pitched slate roof (named after a local landowner, Storey Maskelyne), which was demolished in 1924. The site of the original inn is east of the centre, on the northeastern edge of the Pont ar Daf car park. Buses stop on either side of the A470 outside the centre. The car park at Pont ar Daf, from the Storey Arms centre, is the most popular access point for tourists and walkers to Pen y Fan. The car park, which has space for around 50 cars, is owned by