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 1,300 meters the cave further divides into numerous branches.
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.
