Aven Armand - Entrée artificielle

The cave opens in Jurassic limestones. The Aven consists of an access shaft and a vast sloping chamber. The main chamber, whose floor lies at -100 metres below the surface, is 110 m long, 60 m wide and an average of 45 m high. The cave's vertical extent is 197 metres.

At the bottom of the chamber is a "forest" of large stalagmites whose varied forms (drapes, organ pipes, verticals, "stack of plates", etc.) are explained — among other factors — by the height from which the water drops fall, the different flow speeds, the chemical nature of the water, etc. The main chamber houses a forest of more than 400 stalagmites, including one 30 m high, one of the tallest in Europe. The cave's stalactites are small compared with those of other caves: the high speed of water infiltration through the ceiling wall leaves little limestone deposition. Most of the limestone is thus deposited on the stalagmites.

It was through the access shaft that Louis Armand and his companions arrived.

Source: collaborative encyclopedia Wikipédia, in French > article "Aven Armand": https://fr.wikipedia.org/wiki/Aven_Armand