the world's deepest known cave, located in the Alps near the town of Samoëns, Haute-Savoie département, Rhône-Alpes région, southeastern France. The highest of the limestone cave's eight entrances is located above Samoëns at an elevation of 7,428 feet (2,264 m). The original entrance was discovered by the Groupe Vulcain (from Lyon, France) in 1964. The later discovery of higher entrances and successive cave dives that penetrated past water sumps resulted in a total depth for the cave of 5,036 feet (1,535 m). The total length of Jean Bernard is 11.1 miles (17.9 km).