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.
Bill Steele (cave explorer)
Charles William Steele, Jr. (born October 17, 1948), known as “Bill Steele,” is a cave explorer. He is a speleologist who has led and participated in expeditions to many of the longest and deepest caves in the USA, Mexico, and China. He has explored more than 2,500 caves across North America and Asia and has written two books chronicling his expeditions: "Yochib: The River Cave", and "Huautla: Thirty Years in One of the World's Deepest Caves.” TV shows such as National Geographic Explorer, NOVA and How’d They Do That? have aired programs on his expeditions.