Slovenia's show caves, and how to pick the right one

The big two, Postojna and Škocjan

At 19.5 km, according to the government, Postojna Cave is the longest show cave in Slovenia, and the tourist board claims it is the only karst cave with its own railway. The guided visit lasts about an hour and a half and covers roughly 5 km, starting on a train that has been carrying visitors into the hill for more than 140 years. The olm lives here too, the so-called human fish, the largest cave animal in the world, which can live to around a hundred. That is why it is busy, and why an early slot pays off.

The Škocjan Caves are a different experience altogether. On the World Heritage List since 1986, UNESCO counts them among the biggest subterranean river gorges known, carved by the Reka, with passages up to 150 m high and more than 120 m wide. The Martel chamber alone tops two million cubic metres. You do not come here for pretty stalactites; you come to feel tiny. If I had to keep just one, it would be this.

Postojna or Škocjan in one day?

My rule is simple. Travelling with young children, older relatives or very little time, go to Postojna, because the train does most of the work and Predjama Castle is next door. If you walk comfortably and care more about drama than convenience, go to Škocjan. With two nights in the area, do both, Škocjan first.

One thing worth knowing before you book Postojna is that the operator sells tickets on its own website and warns about unofficial resellers. In October 2026 its packages ran from €34.90 to €84.50 per adult, depending on what was included.

Smaller caves worth the detour

The Karst hides plenty more. Vilenica Cave, near Lipica, opens with the Dance Hall, where the Vilenica International Literary Festival holds its closing event each year; the tourist board admits its age has never been pinned down. Divača Cave once received Crown Prince Rudolf and Sigmund Freud. Dimnice had a water supply system built inside it during the Second World War, and Planina, on the edge of Planinsko polje, is the largest water cave in the country.

Križna jama is the adventurous pick, with emerald lakes crossed in the company of cavers and chambers where the bones of a hibernating cave bear were found. It will not suit everyone, which is exactly why I rate it.

To sleep close to everything, search places to stay in Postojna on Expedia and filter by area before price.

Caves beyond the Karst

Closer to the capital is Županova jama, near Grosuplje, where scenes from the Winnetou and Kekec films were shot. In the Savinja Valley, Pekel Cave is more than three million years old, and the cave under Mt Raduha is the highest show cave in the country, with ice and flowstone side by side. In Koroška, the old lead and zinc galleries of the Mežica mine can be explored by bike or kayak.

Visiting without doing damage

Expect about 10 °C, damp air and slippery floors, so bring a layer and shoes with grip whatever the weather outside. Some caves can only be entered with a licensed cave guide, and in many you will be given a helmet and torch. The tourist board asks you not to touch formations that took thousands of years to grow, to keep the noise down and to use light sparingly. Water from these caves often ends up in village taps above, which is worth remembering.

For the landscape on top, my guide to the Slovenian Karst explains why there are so many caves here in the first place.

To sleep close to everything, search places to stay in Postojna on Booking.com and filter by area before price.