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.
Endless Caverns
The present mapped extent of Endless Caverns is , making it the 20th longest cave in Virginia and the 176th longest in the United States. Its deepest measured point is below the surface.