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.
Lurgrotte
The Lurgrotte karst cave is the largest cave in the Eastern Alps of Styria, Austria. It is located about north of Graz and crosses the Tannenben karst region. The cave has two accessible entrances, one at the village of Semriach and the other at the village of Peggau. At the Semriach entrance, the Lur River sinks into the cave. At the Peggau entrance, the Schmelz River emerges from within the cave, flowing to the west and eventually joining the Mur River.