Team Petzl retraces the steps of the first explorers (Joe Berger, Fernand Petzl, Jean Lavigne, Georges Garby, Pierre Chevalier…). Thanks to extraordinary images from the film “Siphon-1122” (directed by Georges Marry in 1962 and produced by Jack Lesage) relive the intensity of the first descent in this now well-known, must see cave.