Since Jules Verne wrote his influential novel “Journey to the Center of the Earth,” the aim to discover the deepest place below the surface has sparked the imaginations of generations of explorers, adventurers and scientists. Those in search of the deepest known cave on the planet are always lead to Georgia’s breakaway region of Abkhazia. Deep in the mountains of the Arabika Massif, these record-breaking caves can be found—the four deepest caves in the world, including Krubera Cave (also known as Voronya Cave, just to keep it interesting), second-deepest in the world, to nearby Veryovkina Cave.

The Arabika Massif in the Western Caucasus constitutes one of the largest karst massifs on Earth, but despite its enormous potential to scientists, the area, including Krubera Cave, has been woefully under-explored. One of the reasons is the remoteness of the area, which is only accessible for up to four months a year, but the main obstacles for scientists have been the numerous political conflicts in Abkhazia, which continue until today.

Krubera Cave was declared the world’s deepest cave in 2001 when Ukrainian speleogolists reached a depth of 1,710 meters, thereby exceeding the previous known reigning champion in the Austrian Alps. At a depth of 1,500 meters, a subterranean waterfall of near-freezing water has flooded a branch of the cave system, while the main branch continues to a depth of 2,140 meters, where a terminal siphon marks the end of the cave. In 2018, Veryovkina Cave took over the title, at 2,212 meters deep—more than 1.3 miles. 

The Ukrainian speleogolists needed a staggering 14 days to reach the siphon at the end of the cave. A number of endemic fauna has been found at all levels of depth within the cave, including spiders, scorpions, beetles, as well as stygofauna like shrimps and amphipods.