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.
Gagra Range
The range is mostly made up of limestone, with pronounced karst topography and is characterized by many deep canyons created by rivers. The deepest cave in the world, the Veryovkina Cave, is located in the Arabika Massif of the Gagra Range.