Krubera Cave

Krubera Cave, in the Arabika Massif of the Gagra Range in Abkhazia's Western Caucasus, is the deepest known cave on Earth, reaching 2,224 meters below its highest entrance. It formed through karst dissolution within Lower Cretaceous and Upper Jurassic limestone, along with interbedded marls, sandstones and chert, its vadose shafts and steep meandering passages shaped by groundwater following faults and fractures rather than simple folds in the rock. Georgian speleologists first explored the cave in the early 1960s and named it for the Russian geographer Alexander Kruber, but the deepest sections were reached only much later, when Ukrainian teams pushed past 2,000 meters in 2004, the first time any cave had been explored to that depth, with further diving expeditions extending the known depth through 2024.