Abismo Guy Collet
The Abismo Guy Collet (SP-090) is the deepest cave in South America, and the deepest in the world that is formed in quartzite. Located in a tepui in northern Brazil near the border with Venezuela, this cave was first explored by cavers in 2006 to a depth of 671 meters.
Dent de Crolles
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 Pierre Chevalier and the rest of 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.