Slovenian Karst Wonders

The Postojna region serves as the cradle of karstology, featuring some of the world's most significant subterranean landmarks. This collection includes the 24-kilometer Postojna Cave system, renowned for its diverse stalactites and the rare olm salamander. Nearby, the 13th-century Predjama Castle is built directly into a 123-meter cliff, concealing a network of secret tunnels. The list also covers the confluence of the Pivka and Rak rivers in Planina Cave and various collapse sinkholes like Unška koliševka, which contains abandoned military fortifications.

Postojna Cave

Postojna Cave is a 24.34 km long karst cave system near Postojna, southwestern Slovenia.

Predjama Castle

Nested in a 123-meter-high rocky cliff, this is probably the most haunted castle in Slovenia – beautiful during the day and absolutely…

Planina Cave

Planina Cave, formerly also Little Castle Cave after Little Castle in the vicinity of its entrance, is one of the longest Slovenian active…

Pivka Jama

Accessible via 600 steps, this cave offers a close view of the underground Pivka River as it continues its path through the karst interior toward the Black Cave.

Črna jama

Known for its unique dark-colored stalactites and stalagmites, this cave is connected to the Postojna system by an artificial tunnel and features massive limestone blocks.

Otoška jama

A small, dry, horizontal cave that forms part of the Postojna system. It is characterized by its natural lighting and has served as a filming location for several movies.

Unška koliševka

A 100-meter deep collapse sinkhole featuring a network of abandoned underground tunnels and bunkers built by the Italian army between the World Wars.