Ogof Ffynnon Ddu - The Cave of the Black Spring

“Ogof Ffynnon Ddu – The Cave of the Black Spring” offers a fascinating deep-dive into one of Britain’s most remarkable subterranean systems. Located beneath the moors of South Wales, this extraordinary cave stretches over 59 km and plunges to a depth of 274 m, making it the longest and deepest cave in the UK.

Through a vivid mix of geology, exploration narrative, and descriptions of dramatic passages, waterfalls, limestone formations, and underground riverways, the book invites readers into a maze-like world of natural wonder. With historical accounts of early discovery by the South Wales Caving Club, notes on cave ecology and conservation, and practical insights for the adventurous explorer, it’s an essential guide for cavers, geologists, and anyone curious about the mysterious depths beneath the Brecon Beacons.