The geological features of Wales’ Ogof Ffynnon Ddu National Nature Reserve presented by Dr. Keith Ball. He is a retired British Geological Survey geologist and life-long speleologist.

This is the first of 4 instructional videos describing and explaining the geological features of the above and below ground landscapes in the OFD Nationl Nature Reserve in the central Brecon Beacons. This video introduces the main features and rock types. The presenter is Dr Keith Ball, retired from the British Geological Survey and also a life-long speleologist. The films will be published progressively over the next few weeks.