Velebit caves
The "Lukina jama" cave is 1431 m deep (2013), the deepest cave in Croatia, 14th deepest cave in the world and the deepest cave in southeast Europe. At its foot, there are ponds and streams including one of the largest known colonies of subterranean leeches ("Erpobdella mestrovi"), which has been ascertained to represent a new species, genus and also family. Other species discovered in the system, include the air-breathing land snails "Zospeum tholussum". Like Lukina jama, Slovacka jama, Velebita and Meduza are also located at the "Hajdučki i Rožanski kukovi" special reserve, a dedicated part of the Sjeverni Velebit national park.
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.