Ogof Ffynnon Ddu

OFD was discovered in 1946 through digging by Peter Harvey and Ian Nixon, members of the newly formed South Wales Caving Club.

The passages and chambers of Ogof Ffynnon Ddu weave a tortuous path beneath the east side of the Tawe Valley.

The stream passage cuts through black limestone producing waterfalls, rapids, deep potholes and scalloped walls.

[14] Deep cracks in the vast expanse of stony moorland above provide habitats for plant life, including the lily of the valley and wood anemone, and mossy saxifrage (Saxifraga hypnoides) grows on the limestone outcrops.

It was designated as an NNR because of its unique geology, floristic diversity, its industrial past and its subterranean animal and plant life.

Part of the interior with a terraced cascade and three standing and climbing cave explorers wearing safety equipment