Kostanjevica Cave

Kostanjevica Cave, Kostanjeviška jama in Slovene, is a small show cave in the hills just outside Kostanjevica na Krki, in Lower Carniola in southeastern Slovenia. It is far less famous than Postojna or Škocjan, and that is part of its charm, since the cave is modest in scale, quiet and easy to visit as part of an outing to the town. Dolenjska is not the most famous cave region of the country, but the limestone hills of the area hide a number of underground systems, and this one was opened to visitors in the twentieth century after being discovered more or less by chance.

Inside, a guided route leads along paved paths through chambers decorated with the classic formations of limestone caves. Stalactites hang from the ceilings, stalagmites rise from the floors, and flowstone and curtains of calcite drape the walls, all of them built up drop by drop over thousands of years as water seeps through the rock and deposits dissolved lime. The paths are lit, and the guide explains how the cave formed, how the formations grow, and what lives in the dark. Temperature inside is cool and steady all year, so a jacket is a good idea even on a hot summer day, and shoes with grip help on damp steps. The tour is short and well suited to families with children, though the stairs and low sections mean that it is not suitable for people with limited mobility.

Tours are scheduled rather than continuous, and the cave is usually open only for part of the year, with more frequent tours in summer, so check the current timetable and book ahead if you can. Photography rules vary, so ask the guide before taking pictures. Please do not touch the formations, since oils from the skin can stop them growing.

Kostanjevica na Krki gives plenty of reasons to stay longer. The town sits on an island in the river Krka, and its Cistercian monastery houses the Božidar Jakac Art Museum with its sculpture park. The Cerkev Sv. Jakoba, the church of St James, the Cvelbar Oak, the Krakovo Forest, a large lowland oak wood good for walks, and the Romarska pilgrim route are all within reach. The surrounding hills produce Cviček, the light red wine of Dolenjska, and cellars welcome visitors.

The cave suits families, curious travellers and anyone building a day around Kostanjevica. Allow about an hour for the tour and travel. After the tour, a stroll through the town is a good way to round off Slovenia’s quietest cave outing.