In January 2001, the expedition of the Ukrainian Speleological Association explored Krubera (Voronja) cave in Arabika to a record-breaking depth of 1710m. For the first time in the history of speleology, the world's deepest cave has been explored outside of Central/Western Europe. It stands alone as the most remarkable achievement in super-deep exploration of the recent decades, the largest single breakthrough in depth since 1975. Overcoming of the previous depth record of Lamprechtsofen-Vogelschacht in Austria by 80m is particularly impres- sive compared to the three previous records, each of which raised the bar no more than 20 meters (to - 1602m in 1989, -1610m in 1998, -1632m in 1998). This article briefly describes speleological potential of the Arabika massif and history of its exploration and gives some details of the Krubera cave and the recent record-breaking exploration. ARABIKA MASSIF: SPELEOLOGICAL, GEOLOGICAL, AND HYDROLOGICAL FEATURES The Arabika Massif is one of the largest limestone massifs of the Western Caucasus. It is located in Abkhasia, the republic that officially belongs to Georgia although claims itself as an independent state. The latter is the matter of still unre- solved political contradictions between Abkhasia and Georgia that caused the major conflict in 1993-1994. The massif has strongly pronounced glaciokarstic surfaces at elevations rang- ing between 1900 to 2500m, and is com- posed of Lower Cretaceous and Upper Jurassic limestones. In the central part of Arabika the formations of Cretaceous age remained only in some ridges and peaks, as well as in patches within trough val- leys. The core part of the massif is com- posed of Upper Jurassic strata that dip continuously to the Black Sea shore and submerge below the modern sea level (Figure 1, profile). Geologically, Arabika corresponds to the large anticline of the sub- Caucasian (NW-SE) direction with the gentle dipping south-western mega- flank (complicated by several low-order folds of the same direction) and steeply dipping north-eastern flank. The massif is severely tectonised, with the fault-block structure strongly controlling both cave development and groundwater flow sys- tems (Klimchouk, 1990). On the north- west, northeast, and east, Arabika is bor- dered by the deeply incised canyons of the Sandripsh, Gega and Bzyb rivers. The latter separates Arabika from the adjacent Bzybsky Massif, another area of major speleological significance in the Western Caucasus with Snezhnaja Mezhonogo (-1370m), Pantjukhina (- 1508m) caves and many other consider- able caves. Glacial trough valleys formed during the late Pleistocene glaciations are the main features of the central part of the Arabika massif (Klimchouk, 1984), with ridges and peaks in-between them. The central part is shown in beige tint in Figure 1 and indicates the area above the tree line at approximately 1800-1900m. The highest peak (the Peak of Speleologists) rises to an altitude of 2705m. Some low-altitude ridges covered with forest stretch from the central part towards the Black Sea. Among several hundred caves known in the Arabika massif, some deep caves were explored during the 1980s (indicat- ed by red dots in the Figure 1), including Iljukhina system (-1240m), Arabikskaja system (Kujbyshevskaja-Genrikhova Bezdna; - iliUm), Dzou Cave (-1080m), Moskovskaja Cave (-970m), Sarma Cave Page 16 Caves.com In a search for the route to 2000 meters depth: The Deepest Cave in the World in the Arabika Massif, Western Caucasus by Alexander Klimchouk and Yury Kasjan--Ukranian Speleological Association Photographs by Oleg Klimchouk, Denis Provalov, Yury Kasjan, Vladimir Kisseljov, and Alexander Klimchouk