Boybuloq Cave
The cave is the deepest known cave in Asia having been explored to a depth of from the entrance. At the lowest discovered level a water-filled siphon blocks further exploration. It is thought that the cave has the potential to be the deepest known cave in the world, with a theorised depth of making it deeper than the Veryovkina Cave. The explored length of the cave is .
Pit cave
During World War II, a team composed by Pierre Chevalier, Fernand Petzl, Charles Petit-Didier and others explored the Dent de Crolles cave system near Grenoble, France. It became known as the deepest cave in the world () at that time. The lack of available technical equipment during the war forced Chevalier and his team to innovate and develop their own. The scaling-pole (1940), nylon ropes (1942), use of explosives in caves (1947), and mechanical rope-ascenders (Henri Brenot's "monkeys", first used by Chevalier and Brenot in a cave in 1934) can be traced historically to the exploration of the Dent de Crolles cave system.