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.
Pierre Chevalier (caver)
Chevalier first visited the Trou du Glaz entrance in 1935, and was struck by the possibility of exploring beyond what was at the time considered technically possible. With Fernand Petzl, Charles Petit-Didier and others, Chevalier completed explorations that connected four entrances (Trou du Glaz, Guiers Mort, P40 and Grotte Annette) and established the Dent de Crolles as the deepest cave system in the world (-658m).