Dent de Crolles
The Dent de Crolles () is a karstic mountain (2,062 m) of the Chartreuse Mountains range, north east of Grenoble, Isère, France. It has a characteristic "tooth-like" profile and is easily recognizable in the Isère Valley (Grésivaudan) in the Grenoble area. The French word "dent" means tooth and "de Crolles" is derived from the town of Crolles, located next to the mountain. Geography. The Dent de Crolles is a karstic mountain (2,062 m) of the Chartreuse Mountains range, north east of Grenoble, Isère, France. The French word "dent" means tooth and "de Crolles" is derived from the  town of Crolles, located next to the mountain. It is easily recognizable in the Val-d´Isère (Grésivaudan) in the Grenoble area. Cave system. The réseau de la Dent de Crolles, which lies beneath the summit plateau, is one of the most complex and longest cave systems in Europe, and is considered to be one of the birth places of modern caving. Its first detailed exploration was during World War II by a small team of French cavers which included Pierre Chevalier, Fernand Petzl, and Charles Petit-Didier. Their explorations saw it become the deepest cave in the world at the  time with a depth of . The lack of available equipment during the war forced the team to develop their own equipment, leading to technical innovation. The first use of the single rope technique with prusik and mechanical rope-ascenders (Henri Brenot's "monkeys", first used by Chevalier and Brenot in a cave in 1934) can be directly associated with its exploration. Since 1946, the cave has undergone intense and continuous exploration. As of 2021, thirteen separate entrances have been discovered. The highest is the Gouffre Bob Vouay at an altitude of located close to the summit, and the lowest is  the main resurgence, the Grotte du Guiers Mort at an altitude of , giving a depth of . It is known to include more than of passages. The cave system is popular for the various through trips that the various entrances allow.