1) Brecon Beacons 
The Caerfanell is a river which rises in the central section of the Brecon Beacons National Park in Powys, Wales. It rises as Blaen Caerfanell on the plateau of Gwaun Cerrig Llwydion and drops steeply down southeastwards into the head of Glyn Collwn before turning east then north-east into Talybont Reservoir. It emerges from the hydro turbine bene...