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.
GB Cave
The cave was first entered on 19 November 1939, after ten months of digging, by the University of Bristol Spelæological Society, and was named in recognition of the two members, F. J. Goddard and C. C. Barker, who had done most of the work involved in its discovery. The cave is located within the Cheddar Complex and the 17-acre GB Gruffy nature reserve and is close to Charterhouse Cave, the deepest cave in the region.