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.
Baumann's Cave
The cave is frequently mentioned in the early scientific and travel literature as it has been open to the public with guided tours since 1649 when Valentin Wagner was installed as first cave guide. Baumann's Cave is probably the oldest regularly frequented and guided show cave, at least in Germany. Amongst its most famous visitors was Johann Wolfgang von Goethe. The cave's biggest chamber, the "Goethesaal", is named after him and is fitted with seats and a stage for concerts and plays.