Ogof Ffynnon Ddu: at the cave entrance
Ogof Ffynnon Ddu, also known informally as OFD, is a cave under a hillside in the area surrounding Penwyllt in the Upper Swansea Valley in South Wales. It is the second longest cave system in Wales and the deepest in the United Kingdom. Judging by the age of some of the cavers here I guess they weren't going that deep today.
隨機精選照片
