La Mine de Rien

One enters a straight, steep gallery; 5 metres further on, one arrives at the ceiling of a natural shaft (+ 2). Just after, in the left wall, a skylight reachable by a small 2-metre climb gives access to two small galleries 17 metres in development that return towards the surface. The main gallery continues to descend, narrowing, to end in a squeeze at 18 metres from the entrance. Just before, a low, narrow passage leads into a descending flat-out squeeze down to a vertical constriction. At the foot on the right, a small narrow conduit opens into a small concretion-filled pocket (-18). On the other side, a narrow descending passage opens into a fine joint fissure (- 19).

To the north, a fine gour; above it a choked chimney 9 m high; towards the south, a large joint fissure (10 m high) about one metre wide on average, down which one descends by a 5 m step. Below, the descent continues through concretion-covered blocks and one reaches the low point at - 30 m. Above, the joint fissure rises gently then more steeply up to - 17, stopping on blocks. A little before, on the right, another committed climbing ascent is choked at - 17 m.

White limestones of the lower Emsian (Devonian).