Velebit
There are hundreds of "holes" on Velebit. It has the largest and deepest caves in Croatia. The three-part "Lukina jama" cave is 1392 m deep, making it one of the deepest caves in the world, and the deepest in southeast Europe, while the "Slovačka jama" is 1320 m. What makes it unique is that it is completely vertical, steepest in the world. At the bottom of the pothole is a water course or siphon with branches that are still unexplored. A kind of leech was discovered in the pothole, which has been ascertained to represent a new species, genus and family; it has been named "Erpobdella mestrovi".
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.