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.
GB Cave
The cave was first entered on 19 November 1939, after ten months of digging, by the University of Bristol Spelæological Society, and was named in recognition of the two members, F. J. Goddard and C. C. Barker, who had done most of the work involved in its discovery. The cave is located within the Cheddar Complex and the 17-acre GB Gruffy nature reserve and is close to Charterhouse Cave, the deepest cave in the region.