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.
Siddha cave
Siddha Cave or Siddha Gufa is a cave located in Bimalnagar, Tanahu District, Nepal. It is the largest cave in Nepal and second largest cave in South Asia. It's around 0.5 kilometer inside and around 2500 people can feet inside. If you would like to go over Siddha Cave then you have to vehicle from Kathmandu on Prithvi Highway which will take around 4 hours to Bimalnagar, then you have to walk up hills on steps. It will take around 1.5 hours from Bimalnagar to reach to Cave.