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.
Gap Cave
Gap Cave is located just underneath Pinnacle Overlook in the Cumberland Gap National Historical Park, Lee County, Virginia. Currently, the cave has a surveyed length of 18.5 miles and is the 42nd longest cave in the United States and 154th in the world. There are six known entrances: the Gap Cave Entrance (also known as the King Solomons Cave Entrance), an artificial entrance, known as the Cudjo's Cave Entrance, the Stream Entrance, the Soldiers Cave Entrance, the Big Saltpeter Cave Entrance, and the Wellhole. All lead into the same cave, Gap Cave.