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.
Macocha Gorge
The Macocha Abyss (Czech: "Propast Macocha", literally the "Stepmother Abyss"), also known as the Macocha Gorge, is a sinkhole in the Moravian Karst cave system of the Czech Republic located north of the city of Brno, near the town of Blansko. It is part of the Punkva Caves and the Punkva River flows through it. The sinkhole is about 138.7 meters deep, which makes it the deepest of its kind (light hole type) in Central Europe.
It is a popular tourist attraction for casual visitors to the region, in addition to cavers and advanced technical divers.