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.
Ghar Parau
A British led caving expedition to the Zagros Mountains in 1971 led to the discovery of the cave. The cave was explored to a depth of 742 m by the time the expedition was forced to return to the surface. The explorers believed that the cave might go on much further, possibly surpassing the Gouffre de la Pierre-Saint-Martin system, which at that time was the world's deepest known cave.