Krubera Cave
The difference in elevation of the cave's entrance and its deepest explored point is . It became the deepest-known cave in the world in 2001 when the expedition of the Ukrainian Speleological Association reached a depth of which exceeded the depth of the previous deepest-known cave, Lamprechtsofen, in the Austrian Alps, by . In 2004, for the first time in the history of speleology, the Ukrainian Speleological Association expedition reached a depth greater than , and explored the cave to . Ukrainian diver Gennadiy Samokhin extended the cave by diving in the terminal sump to 46 metres' depth in 2007 and then to 52 m in 2012, setting successive world records of 2,191 m and 2,197 m, respectively. Krubera is one of the two known caves on Earth deeper than 2,000 metres.
Krubera Cave
The biocenosis of Krubera-Voronja is composed of more than 12 species of arthropods of several groups, such as pseudoscorpions, spiders, opiliones, crustaceans, springtails, beetles and dipterans. Krubera-Voronja cave is inhabited by endemic species, including four springtails discovered during the CAVEX Team expedition of 2010: "Anurida stereoodorata", "Deuteraphorura kruberaensis", " Schaefferia profundissima", and "Plutomurus ortobalaganensis"; the last of these is the deepest terrestrial animal ever found on Earth, living below the cave entrance. The beetle "Catops cavicis" inhabits Krubera-Voronja cave and also several caves around the Ortobalagan valley. The subterranean amphipod crustacean "Kruberia abchasica" caught by Gennady Samokhin in August 2013, during dives in the siphon 'Dva Kapitana', dwells at the deepest part of the Krubera Cave (at the depth of -2,175 metres).