Postojna Cave, near Postojna, southwestern Slovenia, Europe

Postojna Cave, near Postojna, southwestern Slovenia, Europe

Postojna Cave, near Postojna, southwestern Slovenia, Europe

Postojna Cave, near Postojna, southwestern Slovenia, Europe

Predjama Castle, built in mouth of cave, near Postojna, Slovenia, Europe

Postojna Caves, Postojna, Slovenia, Eastern Europe

Postojna Caves, Postojna, Slovenia, Eastern Europe

Postojna Caves, Postojna, Slovenia, Eastern Europe

Predjama castle, around Postojna, Notranjska, Slovenia

Predjama Castle, Predjamski Grad, near Postojna, Inner Carniola, Slovenia, Europe

Tourist walking on a concrete walkway inside the famous postojna cave in slovenia, admiring the stalactites and stalagmites during a guided tour

Tourists walking on a footpath and exploring the magnificent postojna cave in slovenia, a popular tourist attraction

Tourists walking on illuminated footpath inside the famous postojna cave, a karst cave system near postojna, slovenia

Cave castle Lueg, predjamski grad, Predjama, near Postojna, Slovenia, Europe

Cave castle Lueg, predjamski grad, Predjama, near Postojna, Slovenia, Europe

Predjama Castle, Predjamski Grad, near Postojna, Inner Carniola, Slovenia, Europe

Predjama Castle, Predjamski Grad, near Postojna, Inner Carniola, Slovenia, Europe