This amazing subterranean cave was discovered in 1897 by locksmith Louis Armand. At the time, he had to descend a 75m-deep well-shaft to the cave. Nowadays, a 200m-long tunnel leads to the foot of the same chimney and to the entrance to the cavern. A grandiose sight awaits visitors in the form of a vast gallery 60m x 100m, and 45m high, home to a veritable petrified forest. Some of the stalagmites have bases measuring up to 3m in diameter and reach a height of 25m.