Caves of Postojna & Škocjan

The karst landscape (the term "karst" actually originates from this region!) of Slovenia is home to some of the most spectacular cave systems in the world. Two of them are absolute must-visits:

Postojna Cave (Postojnska jama)

The most visited cave system in Europe and one of Slovenia's largest tourist attractions. The numbers are impressive: 24 km of surveyed passages (5.7 km of which are accessible), 500,000-year-old dripstones, stalagmites, and stalactites of gigantic beauty. The special feature: An electric train takes you 3.7 km deep into the mountain — like in a Jules Verne novel. Then 1.7 km on foot through the "Concert Hall" (it holds 10,000 people!) and the "Brilliants" — a forest of dazzling white stalactites. The temperature inside is a constant 10°C — don't forget your jacket!

Also famous is the olm (Proteus anguinus), a blind, skin-colored amphibian that lives exclusively in the karst caves of the Dinaric Alps. In Postojna Cave, there is a vivarium where you can observe "baby dragons" (as the Slovenians call them). Entrance: €28.90 (adults). Online pre-booking recommended, as tours often sell out in summer.

Škocjan Caves (Škocjanske jame) — UNESCO World Heritage

If Postojna is the more famous, then Škocjan is the more overwhelming. The Reka River has created an underground canyon that is 146 m deep, 120 m wide, and 2.5 km long — the largest underground gorge in Europe. You stand on a narrow bridge (Cerkvenik Bridge), 47 m above the roaring river below, and the dimensions are so vast that you feel like you're in a cathedral of Earth's history.

The Škocjan Caves have been a UNESCO World Natural Heritage site since 1986 and are less commercial than Postojna: no train, smaller groups, more reverence. The descent into the gorge is more physically demanding (500 steps, 2 km walk). Entrance: €20. The tour lasts about 1.5 hours. Sturdy footwear required.

Which cave to visit?

Both, if time allows — they are only 35 km apart. Postojna impresses with size and dripstone splendor. Škocjan overwhelms with the raw natural power of the underground canyon. If you can only manage one: Škocjan is the more unforgettable experience.