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.
Coral Cave
The Coral Cave () is a marble cave at the northernmost tip of Jämtland, near Ankarvattnet, Sweden. It was discovered in 1985. So far, six kilometres of it have been explored, making it Sweden's longest cave. Members of the public are not allowed to visit the Coral Cave without a guide.