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-Gwryd was developing in North Wales. In May 1898 "The Climbers Club" originated at Pen-y-Gwryd, as it is recorded in its first journal "...its natural birth at Pen-y-Gwryd" and "...its congenial atmosphere... ("The Climbers Club") first struck its roots". The "Climbers Club" is now based at "Helyg" on the A5 between Capel Curig and Ogwen Cottage. In 1870 the "Society of Welsh Rabbits" (c.1865) was founded with the objective of exploring Snowdonia in winter (and as close to Christmas as possible). Ann Owen said in 1895 that the society had written an article "praising Pen-y-Gwryd as an excellent resort at Christmas".