Situated to the south of the village of Fretigney, this very impressive cave has now been classified as a Regional Nature Reserve, as it is an ideal habitat for several species of bat. Its entrance is one of the largest in Haute-Saône, with a large porch 27 m wide and 4 m high. Please note that it is strictly forbidden to enter. An information board is available. Accessible via the Baume Noire footpath.
