Krubera Cave is the deepest known cave on Earth. It is located in the Arabika Massif, one of the largest high-mountain limestone karst massifs in the Western Caucasus region of Georgia.
This mountain block contains several hundred caves that started to develop when the mountains started to rise more than 5 million years ago. Five of these caves are deeper than 1,000 meters; Krubera is 2197 meters deep and is the only known cave on Earth deeper than 2,000 meters.
Krubera Cave is a 16,058 meters long cave system which for most part consists of deep, vertical wells which are interconnected with passages. The cave starts high in the mountains, at an altitude of 2,256 meters, with a narrow entrance. Krubera Cave often is very narrow and had to be carved at many places to allow safe passage. At other places, the passageway is as large as subway tunnel.
At the depth of 200 meters, the cave divides into two main branches: Non-Kuybyshevskaya (explored to the depth of 1,293 m in 2008) and Main (2,197 m deep). At the depth of 1,300 meters the cave further divides into numerous branches.
When speleologists started exploring the cave, one of the hardships they faced were flooded tunnels called “sumps.” When they encounter a sump, cavers have to put on scuba gear and charge ahead. One of the sumps – the deepest one – has been dived up to 52 m depth.
The cave now is very popular destination for the expeditions coming from many countries.