Postojna Cave, Slovenia: What to Know Before You Go
Postojna Cave in Slovenia is one of the country’s most famous attractions—and for good reason. This massive underground wonder is the largest cave in Europe open to tourists and the only one where you can ride a train through its tunnels.
We visited because my kids were fascinated by the olm, also known as the human fish, and I wanted to see what had them so excited. The experience turned out to be even cooler—both in temperature and atmosphere—than I expected. Riding a train through the cave, passing incredible stalactites and stalagmites, felt surreal. Even my boys were impressed, though they couldn’t quite grasp just how old these rock formations really are!
It’s definitely a touristy experience, but one that’s absolutely worth seeing. This guide covers everything you need to know before visiting—how to get there, what to expect, ticket info, and insider tips to help you plan the perfect trip.
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Where Is Postojna Cave?
Postojna Cave is located in southwestern Slovenia, near the town of Postojna. It’s one of the most accessible caves in Europe, sitting right off the A1 highway that connects Ljubljana and the coast.
Here’s how far it is from major destinations:
- Ljubljana to Postojna Cave – 53 km (33 miles), ~45-minute drive
- Lake Bled to Postojna Cave – 105 km (65 miles), ~1 hour 15 minutes by car
- Piran to Postojna Cave – 75 km (47 miles), ~1 hour drive
The cave is part of the Karst region, known for its unique limestone formations and underground cave systems. Nearby, you’ll also find Predjama Castle, a medieval castle built into a cliffside, just 10 minutes away. Many people combine both attractions in one trip.
How to Get from Ljubljana to Postojna Cave
Postojna Cave is about 53 km (33 miles) from Ljubljana, making it an easy day trip from Ljubljana. You can get there by car, bus, train, or guided tour.
By Car – The Fastest & Most Flexible Option
- Drive time: ~45 minutes
- Route: Take the A1 highway (Ljubljana–Koper), exit at Postojna
- Parking: Large paid parking lot near the cave entrance
Driving is the easiest and fastest way to visit. We drove, and it was incredibly easy to find the cave right off the highway. Parking was straightforward, and it’s just a short walk to the entrance. If you’re also planning to visit Predjama Castle, driving makes it much more convenient.
If you’re renting a car in Slovenia, it’s good to know about road tolls, vignettes, and driving rules—we cover all the details in our guide to driving in Slovenia.
By Bus – Budget-Friendly but Less Frequent
- Duration: ~1 hour
- Where to catch it: Ljubljana Bus Station (Avtobusna postaja Ljubljana)
- Tickets: Buy at the station or online
Buses run a few times daily, but schedules vary by season. This is a good option if you’re traveling on a budget, but you’ll need to check return times carefully.
By Train – A Scenic but Less Convenient Option
- Duration: ~1 hour
- Train station: Postojna Train Station (2 km from the cave)
- Getting to the cave: Taxi or 30-minute walk
Trains run frequently between Ljubljana and Postojna, and is a comfortable ride with great views. However, the station is not right at the cave, so you’ll need a taxi or a long walk to reach the entrance.
By Guided Tour – A Hassle-Free Option
If you prefer a stress-free visit, several companies offer Ljubljana to Postojna Cave tours, often combined with Predjama Castle. These tours typically include:
✔ Round-trip transport
✔ Cave & castle entry tickets
✔ A local guide
Tours are more expensive but ideal if you want everything arranged for you. We didn’t take a tour, as we had a car, but if you’d rather skip the planning or driving, there are plenty of great options available. This highly-rated tour covers both Postojna Cave and Predjama Castle with entrance fees and easy transport from Ljubljana. This tour is also an excellent choice, and includes round trip transportation from several spots in Ljubljana.
What to Expect on a Visit to Postojna Cave
A visit to Postojna Cave in Slovenia is a mix of adventure and spectacle. The tour lasts about 90 minutes and includes a train ride through massive underground chambers and a guided walking tour where you’ll see incredible rock formations.
The Train Ride – A One-of-a-Kind Experience
The tour starts and ends with a 4 km train ride, making Postojna Cave the only karst cave in the world with a railway. As the train winds through vast tunnels and enormous chambers, you’ll pass stalactites and stalagmites—some dramatically lit to highlight their size. One of the most stunning spots is the Dance Hall, where Murano-glass chandeliers hang from the ceiling.
The train ride was the real highlight for us. It felt surreal zooming through the cave, passing massive rock formations that looked like something out of a fantasy movie. Even my kids, who were most excited to see the olm, were impressed by the towering rock formations and the sheer scale of the cave.
The Walking Tour – Exploring the Underground World
After the train ride, the tour continues on foot for about 1 km. The path is accessible, with no stairs, though there are some inclines. Along the way, you’ll see some of Postojna Cave’s most famous formations:
- The Hall of Pillars – The first stop after leaving the train.
- The Russian Bridge – Built by Russian prisoners of war in 1916.
- Briljant (Brilliant) – A 5-meter-tall pure white stalagmite, one of the cave’s most famous formations.
- The Concert Hall – A massive cavern with incredible acoustics, used for concerts and a live nativity scene at Christmas.
Seeing the formations up close was even more impressive than we expected. My kids couldn’t quite grasp how old they were, but they loved pointing out different shapes in the rocks. The one called Brilliant was their favourite—it really does stand out!
Cave Temperature & What to Wear
No matter when you visit, Postojna Cave stays at a cool 10°C (50°F) year-round. Even in the middle of summer, the temperature inside doesn’t change, so it’s a good idea to bring a warm sweater or light jacket.
The cave floor can be damp and slightly slippery in places, so wear comfortable, non-slip shoes—hiking shoes or sturdy sneakers are best.
For more tips on what to pack for your trip, check out our guide to what to pack for Slovenia.
The Baby Dragon – Spotting the Olm
Near the end of the walking tour, you’ll have the chance to see one of Postojna Cave’s most unique creatures—the olm, also known as the human fish or “baby dragon.” This pale, blind salamander has adapted to life in complete darkness and can survive up to 10 years without food.
📖 Psst, you can read more cool facts – plus download a mini activity book – in these Fun Facts About Slovenia.
Since olms live deep in the cave away from light, they’re hard to spot, especially with large tour groups passing through. We only got a quick glance as we were at the back of our group, so if you’re hoping for a better look, the Vivarium near the entrance offers another chance to see them up close.
Other Attractions at Postojna Cave
If you have extra time, there are a few additional attractions near the cave entrance that are worth checking out.
The Vivarium
This cool exhibit offers a closer look at the cave’s unique creatures, including the famous olm (baby dragon). The dimly lit space mimics the cave environment, and the tanks have red light buttons so visitors can get a better view of the animals inside. My kids loved seeing the olm up close after only catching a quick glimpse on the tour. (see the photos above)
Expo Cave Karst
This interactive exhibit dives into the geology and history of the Karst cave system. It’s great for adults or older kids who want to learn more, but to keep younger kids engaged, an olm and a beetle lead them through the exhibition. There’s also a small section on butterflies and a train car kids can sit in.
Both of these exhibits are included in the full combo ticket or can be visited separately. They’re self-guided, so you can explore at your own pace.
How Much Time Do You Need?
The Postojna Cave tour lasts about 90 minutes, including the train ride and walking portion. However, you’ll want to allow at least 2 to 2.5 hours for your visit, factoring in time for ticket pickup, waiting for your tour to start, and exploring the area afterward.
Many people combine a visit to Postojna Cave and Predjama Castle in one day, as they’re only 10 minutes apart. However, we decided to split them over two days since the combo ticket allows visits on separate days. This gave us more time to explore without feeling rushed.
If you do plan to visit both in one day, allow at least 4–5 hours, as the self-guided audio tour at Predjama Castle takes about an hour. If you’re adding the Vivarium or stopping for food, plan for an extra 30–60 minutes.
Postojna Cave Tickets & Prices
Tickets for Postojna Cave can be purchased as a single entry or as part of a combo package that includes Predjama Castle, the Vivarium, or Expo Cave Karst. A basic cave ticket costs €29.50, while the combo ticket with Predjama Castle starts at €39.90. If you want to visit the Vivarium and Expo Cave Karst as well, the full package is €47.60.
We chose the full bundle since the boys were excited to visit the Vivarium and see the olms, and it was definitely worth it. If you’re interested in the castle or other exhibits, the combo tickets offer the best value.
Tickets are available at the entrance or online on their website in advance. We had no problem buying tickets on-site, but if you’re visiting in summer or on a busy weekend, booking ahead is a good idea to avoid long lines.
Best Time to Visit Postojna Cave
Postojna Cave is open year-round, but the experience varies depending on the season.
Summer (June–August) is the busiest time, with longer opening hours and tours running frequently. However, it also means larger crowds, especially in July and August when Slovenia sees the most visitors. We visited Postojna at the beginning of June, and it was already busy! If you’re visiting in summer, try to go early in the morning or later in the afternoon to avoid peak crowds.
Spring and fall (April–May & September–October) are ideal times to visit. The weather is still good for exploring Slovenia, and the cave is much quieter compared to summer.
Winter (November–March) is the least crowded, and tours are limited to a few set times per day. If you’re visiting around Christmas, you can see the live nativity scene in the cave, a tradition that’s been running for over 100 years.
Since the cave temperature stays at 10°C (50°F) year-round, weather outside won’t affect your visit—it’s more about how busy you want it to be.
Is Postojna Cave Good for Kids?
Yes! Postojna Cave is one of the most kid-friendly caves to visit—especially compared to more challenging caves like Škocjan Cave, which involves steep climbs and long walks.
The train ride is a huge highlight for kids, making the tour more exciting and less tiring. The walking portion is only 1 km and is fully accessible, with no stairs, though there are some inclines.
However, there are a few things to consider:
- The cave is dark and cool (10°C year-round), so younger kids might find it a bit chilly.
- Some areas feel vast and echoey, which could be intimidating for very young children.
- It’s a group tour, so there’s no stopping or turning back—something to keep in mind for kids who don’t like staying in one place for long.
Our Experience: My kids loved the train ride and were excited to see the olm, but they didn’t fully grasp how old the rock formations were. The cave is impressive for all ages, but younger kids might just enjoy the adventure rather than the history.
If you’re visiting with toddlers or babies, strollers aren’t allowed inside the cave, so you’ll need to use a baby carrier instead.
Predjama Castle – Should You Visit Both?
Just 10 minutes from Postojna Cave, Predjama Castle is one of the most unique castles in Europe, built directly into a cliffside cave. Many visitors combine both attractions in one day, but thanks to the combo ticket, you can also visit on separate days—which is what we did.
What to Expect at Predjama Castle
- The castle is a self-guided tour with an audio guide included.
- You can explore medieval rooms, hidden passageways, and cave sections built into the rock.
- The visit takes about an hour, though history buffs might want more time.
I think it’s worth purchasing the combo ticket to include Predjama Castle. A separate ticket costs €11.90, so you may as well add it into the combo—it works out a bit cheaper, and it’s such an impressive, unique castle that you really need to see it.
We visited on a separate day to have more time at each spot, but you could easily do both in one day. In summer, there’s even a free shuttle between the cave and castle (during July and August), making it easy to visit without a car.
Is Predjama Castle Worth Visiting?
If you love castles, history, or dramatic landscapes, it’s absolutely worth seeing. In fact, Predjama Castle is considered one of the most beautiful places in Slovenia, thanks to its dramatic location directly into the cliffside.
➡️ Read more about what to expect Inside Predjama Castle
Where to Stay Near Postojna Cave
If you want to stay close to the cave, there are a few great options, from hotels to camping.
Hotel Jama
Located right at the entrance to Postojna Cave, Hotel Jama is part of the cave complex, offering modern rooms with incredible views. Staying here means you’re just steps away from the cave tour, making it the most convenient option.
🏕️ Camping Pivka Jama
For a more outdoorsy experience, Camping Pivka Jama is a great option. It’s close to the entrance of Pivka Cave and offers basic campsites as well as family-sized bungalows with kitchenettes. We stayed here, and my kids loved the loft-style beds—having a kitchenette was also really convenient. The campsite has a swimming pool and an on-site restaurant, making it a fun and easy place to stay.
There are also hotels, apartments, and guesthouses in the nearby town of Postojna, just a short drive from the cave.
Final Tips for Visiting Postojna Cave
✔ Book tickets in advance if visiting in summer—lines can be long, and tours can fill up quickly.
✔ Arrive at least 20–30 minutes before your tour to pick up tickets and get in line.
✔ Wear a warm sweater or light jacket—it’s always 10°C (50°F) inside the cave, even in summer.
✔ Wear sturdy, non-slip shoes since the cave floor can be damp.
✔ Bring a baby carrier if visiting with a toddler—strollers aren’t allowed inside the cave.
✔ Consider the combo ticket to see the Vivarium, which we thought was well worth it, and Predjama Castle, one of the most unique castles in Europe
✔ If you’re short on time, a guided tour from Ljubljana is a convenient way to visit both attractions without needing to rent a car.
Final Thoughts
Postojna Cave in Slovenia is a truly unique experience, combining an underground train ride, massive cave formations, and the chance to see the rare olm. While it’s a popular tourist attraction, it’s absolutely worth visiting—whether you’re traveling with kids or just love exploring natural wonders. If you have time, adding Predjama Castle makes the trip even more memorable.
For us, this was one of the highlights of our Slovenia trip—the train ride through the cave, the sheer size of the underground chambers, and the excitement of spotting an olm made it an experience we won’t forget. With easy access from Ljubljana, Lake Bled, and the coast, Postojna Cave is one of those places you need to see at least once.
If you’re planning a trip to Slovenia, be sure to check out our other guides, including [the best things to do in Slovenia, tips for exploring Lake Bled with kids and a scenic drive through Vrsic Pass, one of the most beautiful routes in the country. If you’re heading to the coast, don’t miss a day in Koper, or the best things to do in Piran, Slovenia’s stunning seaside town.
