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.
Macocha Gorge
The Macocha Abyss (Czech: "Propast Macocha", literally the "Stepmother Abyss"), also known as the Macocha Gorge, is a sinkhole in the Moravian Karst cave system of the Czech Republic located north of the city of Brno, near the town of Blansko. It is part of the Punkva Caves and the Punkva River flows through it. The sinkhole is about 138.7 meters deep, which makes it the deepest of its kind (light hole type) in Central Europe.
It is a popular tourist attraction for casual visitors to the region, in addition to cavers and advanced technical divers.