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.
Mount Paraw
Paraw cave or Ghar Parau is located in 3050 meter above sea level which is the highest cave in the world and well known as Everest of world caves. this cave has 751 meter depth and with D5 degree of difficulty recognized as one of hardest caves to caving. The British caving team which discovered the cave named their group Ghar Parau foundation. Five professional cavers have lost their lives in this cave.