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 Ty-Nant Pen Ty-Nant Pen Ty-Nant () is a hill within the Snowdonia National Park in Gwynedd, North Wales. Pen Ty-Nant is a member of the Arenig range, just from the small hamlet of Rhyd-uchaf and from Bala. Its parent peak Arenig Fawr is approximately to the west. It is a continuation of a small ridge that begins just to the northwest of Bala and ends at Moel y Garnedd on moorland known as the Gwastadros. On a clear day Pen yr Ole Wen, a member of the Carneddau can be seen above Llyn Celyn, to the northwest. Carnedd y Filiast, Moel