A 'Straw' cave formation in Ogof Ffynnon Ddu cave, Wales, UK'The Columns' Ogof Ffynnon Ddu cave, South Wales, UK"The Nave" in Ogof Ffynnon Ddu cave, South Wales, UK"The Nave" in Ogof Ffynnon Ddu cave, South Wales, UKPorth Yr Ogof cave, Brecon, Wales, UKDinas Rock Silica Mine. the beginning of the flooded section. South Wales, UKDinas Rock Silica Mine. the beginning of the flooded section. South Wales, UKRailway tracks and an incline going deeper into the Dinas Rock Silica Mine, South Wales, UKDinas Rock Silica Mine. the beginning of the flooded section. South Wales, UKRailway tracks and an incline going deeper into the Dinas Rock Silica Mine, South Wales, UKMaen Llia Standing StoneUsk  Reservoir,  Brecon, Wales, UKSgwˆd Isaf Clun-Gwyn. River Mellte, Ystradfellte, Brecon Beacons, Wales,UKRiver Mellte, Ystradfellte, Brecon Beacons, Wales,UKRiver Mellte, Ystradfellte, Brecon Beacons, Wales,UKRiver Mellte, Ystradfellte, Brecon Beacons, Wales,UKRiver Mellte, Ystradfellte, Brecon Beacons, Wales,UKRiver Mellte, Ystradfellte, Brecon Beacons, Wales,UK"Car graveyard" Gaewern Slate Mine, Wales, UK