Krka Cave is a horizontal karst cave in Dry Carniola, central Slovenia, famous as the occasional source of the Krka River. Tucked away in a pocket valley between the villages of Trebnja Gorica and Gradiček, it offers visitors a striking combination of underground passages and a scenic spring lake right at its doorstep.

Water flows into the cave from the Račna Karst Field and emerges just below the main entrance, feeding the Krka's source. During heavy rains, the river bursts dramatically through the entrance, cascading over the stone steps in a torrential waterfall. Inside, the dry part of the cave stretches 210 metres in length and 30 metres in width, with its central section acting as a floodwater channel. At the far end lies a 30-metre sump lake leading into a further tunnel system totalling 490 metres. Decoration is rather sparse, much of it damaged by earthquakes and past vandalism, but the walls reveal numerous striking pareidolic shapes.

How to get there

• Village of Krka — stone stairs lead from the source lake up to the main entrance, easy walk
• Small side entrance — located in the rock wall next to the main entrance

Practical information

• The cave can only be visited with a guide, by prior arrangement
• Locked since 1995 to protect it from further damage
• Main entrance secured with grates
• Occasionally used as a concert venue

Over 30 animal species live in the cave, including bats and olms, and the crustacean Typhlocypris cavicola is found nowhere else on Earth. The polymath Valvasor visited the cave back in the 17th century, and locals once hid here during Ottoman invasions in the 15th and 16th centuries.