Experience · Caves & Underground

Slovenia's underground world

Slovenia has over 13,000 registered caves — more per square kilometre than almost anywhere on Earth. Two stand above all others: Postojna Cave, the grand underground palace, and Škocjan Caves, the wild UNESCO canyon. Both are unmissable. Both are completely different.

🦇 Postojna Cave 🌿 Škocjan — UNESCO 🚂 Underground train 🏔️ World's largest underground canyon Private guided visits

"Postojna is Disneyland underground — spectacular, accessible, unforgettable. Škocjan is Indiana Jones — raw, dramatic, wild. Both are among Europe's greatest natural wonders. If you can, visit both."

Dve jami — dve izkušnji

Postojna & Škocjan

Just 30 km apart, these two caves could not be more different. Here is everything you need to know to choose — or to visit both.

🚂 The grand underground palace · Since 1819
Postojna Cave
Postojnska jama · Notranjska · 1h from Ljubljana
24 kmtotal length
5.7 kmvisited
700mby train
Postojna Cave is known for its large-scale, accessible layout and underground train ride. Discovered and opened to visitors in 1819, it has welcomed over 40 million visitors — including Habsburg emperors, presidents, and rock stars. The underground train carries you 700m into the mountain before the guided walking tour begins through vast chambers filled with extraordinary stalactites and stalagmites — some over 5 million years old.
Underground train — 3.7km ride deep into the cave, a unique worldwide experience
Human fish (Proteus anguinus) — the rare blind cave salamander, endemic to Slovenian caves, on display in the cave aquarium
The Concert Hall — vast underground chamber used for live concerts and events
Brilliant stalactite formations — Spaghetti Hall, White Passage, and the iconic "Brilliant" stalagmite
Predjama Castle nearby — an architectural marvel perched dramatically on the side of a cliff
Year-round visits, fully accessible, family-friendly, no significant physical demands
postojnska-jama.eu
🌿 UNESCO World Heritage · Wild & dramatic
Škocjan Caves
Škocjanske jame · Kras · UNESCO since 1986
6 kmpassages
146 mcanyon depth
1986UNESCO
Škocjan Caves are home to the largest subterranean canyon in Europe at 146m deep — carved by the Reka River. A 4km long magnificent cave with the river constantly roaring down the gorge. The Murmuring Cave is so immense — 3.5km long, 10–60m wide and over 100m high — that it leaves you silent. This is raw, primal nature — not a tourist attraction but a genuine encounter with the power of the underground world.
The Cerkvenik Bridge — crossing the canyon with the river 50m below, in the highest cave hall in Europe — Martel's Chamber
26 underground waterfalls — the roaring Reka River disappears into the mountain and re-emerges in Italy
UNESCO World Heritage — recognised for unique geological features and exceptional biodiversity
Collapsed dolines — dramatic surface formations where the cave roof has fallen in
~400 steps — more physically demanding than Postojna, but manageable for most fit adults
Far fewer visitors than Postojna — a more tranquil and intimate experience
park-skocjanske-jame.si

Which cave is right for you?

🚂 Choose Postojna if...
  • You are travelling with young children or elderly guests
  • You want maximum wow factor with minimum physical effort
  • You love the combination of geology, history, and spectacle
  • You want to see the human fish (Proteus anguinus)
  • You plan to also visit Predjama Castle next door
  • You prefer a fully guided, comfortable, well-lit experience
🌿 Choose Škocjan if...
  • You want a raw, dramatic, unforgettable encounter with nature
  • You are reasonably fit and comfortable with steps and bridges
  • UNESCO heritage and scientific significance matter to you
  • You prefer fewer crowds and a more intimate experience
  • You want to feel genuinely small in the face of nature
  • You love the sound and power of an underground river

Side by side comparison

Category 🚂 Postojna Cave 🌿 Škocjan Caves
ExperienceGrand, accessible, theatricalWild, dramatic, intimate
UNESCO statusNoYes — since 1986
Underground trainYes — 3.7km rideNo — walking only
Physical demandEasy — flat, lit, accessibleModerate — 400 steps, bridges
Highlight featureStalactites, Proteus fish, Concert HallUnderground canyon, roaring river
Tour duration~90 minutes~2 hours
Annual visitors~800,000~90,000 (far quieter)
Cave temperature8–10°C (bring a jacket)12°C (bring a jacket)
Nearby attractionPredjama Castle (10 min)Lipica stud farm (15 min)
Best forFamilies, all ages, first-timersNature lovers, adventurers
🚂 Our verdict on Postojna
"Postojna Cave is a grand cave — organised like Disneyland, but that doesn't take away from the natural beauty." It is the most visited attraction in Slovenia for good reason — the sheer scale, the underground train, and the extraordinary formations make it a bucket-list experience for visitors of all ages. We combine it with a private visit to Predjama Castle for a perfect half-day.
🌿 Our verdict on Škocjan
"Škocjan felt more like an adventure than a tour. There's something about walking alongside an underground river and across high bridges that makes the whole experience feel more real and a bit wild — in the best way." For those who want to be genuinely moved by nature — not entertained by it — Škocjan is the cave. Nothing in Slovenia prepares you for the Martel Chamber.
Our recommendation: If time allows — visit both. They are 30km apart and can be combined in one day. Start with Škocjan in the morning (fewer crowds) and Postojna + Predjama Castle in the afternoon. We arrange private transport, skip-the-line access, and a lunch stop in between. 🏆
Načrtujte obisk

Ready to go underground?

We arrange private transport from your accommodation, skip-the-line entry, expert guides, and the perfect combination of caves, castle, and lunch. One cave or both — your choice.

Begin your journey →