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.
Karst Underwater Research
In January 2013, KUR divers found that Phantom Spring is the deepest underwater cave yet measured in the United States at a depth of .