Trassanel, FR
Grotta: sviluppo 2910m, profondità 171m, nel massiccio Noire (montagne) / Versant méridional de la Montagne Noire audoise, hydrosystème du Minervois-Cabardès.
Listen to the audio guide for Clergue (Aven de) Free on WIP — starts by itself when you arrive, even with the screen off