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.
Castleguard Cave
Castleguard Cave is a limestone cave located at the north end of Banff National Park in the Rocky Mountains of Alberta, Canada. With of surveyed passages (as of 2007), it is Canada's longest cave, and its fifth deepest at . Castleguard Cave ascends gently from its entrance and terminates beneath the Columbia Icefield.