Postojna Caves, Slovenia – A Subterranean Wonderland

Nestled in the karst-landscape of southwestern Slovenia, the Postojna Caves welcome travellers into an underground world of awe and wonder. If you are looking for a spell-binding day trip or a memorable excursion off the beaten path, then the Postojna Caves in Slovenia deliver in spades. In this blog post, I’ll walk you through everything: how to get there, what to expect, why this subterranean marvel is worth your time and tips that will help you make the most of your visit.

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What Makes Postojna Caves, Slovenia Unmissable?

The Postojna Caves (Slovene: Postojnska jama) are among Slovenia’s most iconic natural attractions. With around 24 kilometres of cave system, they are the country’s second-longest network and the most accessible for visitors.

What sets them apart:

• A one-of-a-kind underground electric train ride, giving you a unique vantage point inside the cave galleries.
• Dramatic stalactites, stalagmites, “curtain” formations and cavernous halls – including the famed “Brilliant”, a pure white calcite formation.
• A rare chance to glimpse the enigmatic creature known as the olm (Proteus anguinus), sometimes called the “baby dragon”.
• Its status as a long-running tourist destination (open to the public since the early 19th century) and its excellent accessibility from the Slovenian capital, Ljubljana.

In short: whether you’re drawn by geology, nature, adventure or just seeking something truly different, the Postojna Caves deliver.

History of Postojna Caves, Slovenia

Obviously, the Postojna Caves have been tens of thousands of years in the making, but they have a modern history too. There is evidence (carved graffiti) of human activity in the caves as far back as the 13th century, but the first written record of their existence was in the 17th Century.

The caves’ history of welcoming sightseers began in 1818, when the cave lamplighter, Luka Čeč, discovered a new area while preparing the cave for the visit of the Austrian-Hungarian emperor, Francis I.

Archduke Ferdinand also visited the caves the following year, and popularised it as a tourist attraction.

The Postojna Caves can claim many records. They were lit with electricity before Ljubljana, and even London. The train which takes visitors into the caves is the only one of its type in the world.

The Olm, a blind amphibian found in the caves, was mentioned by Charles Darwin in his famous, “Origin of Species”.

Getting there & planning your visit

Location & access

The caves are located near the town of Postojna, in the region of Inner Carniola. They’re easily reachable by road and rail.

From Ljubljana (the capital of Slovenia), it’s about a 45-minute to 1-hour drive, depending on traffic. If you’re using public transport, there are trains and buses to Postojna and then a short walk or local shuttle to the cave entrance.

If you don’t have a car, or don’t want to use public transport, Postojna Caves are one of the most popular tours offered by Lubljana tour companies. They usually double it up with the equally iconic, Predjama Castle which is close by.

Postojna Caves, Slovenia – Opening times & tickets

The caves are open year-round, though frequencies of tours vary by season:

• In winter (November–March): only a few tours daily (e.g., at 10:00, 12:00 and 15:00)
• In spring/summer (April–October): hourly or near-hourly tours in peak season.

Advance booking is recommended, especially in high season. The tickets are timed, so you’ll need to be sure you’re at the caves punctually so you don’t miss your slot.

Also take note: the cave’s internal temperature stays around 8-10 °C, (46-50 °F) so bring a jacket or warm layer.

What to bring & smart tips

• Warm clothing / layer up: cave temperatures are consistent and quite cool.
• Comfortable walking shoes: the floor may be wet or slippery.
• Camera or phone for photos: many formations and the train ride make for great shots.
• Pre-book your ticket and arrive 15 minutes early for check-in.
• If using public transport, check the return schedule so you’re not caught waiting too long.

Best Time to Go

To avoid crowds, early morning tours are ideal. In summer you’ll encounter more visitors; in spring/autumn the atmosphere is a little more relaxed. Trips in the winter are also possible, though fewer tours are available.

The Experience: What you’ll see in Slovenia’s Postojna Caves

From the moment you step into the portal of the Postojna Caves, you enter another world. Here’s a breakdown of what to expect:

The Train Ride – Unique to Slovenia’s Postojna Caves

One of the highlights: you board the underground train which takes you into the depths of the cave system. The train is historic and adds a sense of old-world adventure.

The train ride is great fun. You career through the tunnels deeper into the cave complex. It’s a bit like a roller coaster ride. Just when you think you’re going to crash into a wall, the train flicks to one side. I’m not particularly tall, but even I was ducking.

Walking tour through cavernous halls

After the train ride you continue on foot through illuminated galleries, past enormous stalactites and stalagmites, and into enormous halls (some big enough to hold thousands of people). For example, one ,“Grand Hall” can hold up to 10,000 visitors.

Some formations to look out for:

• “Skyscraper” – a 16-metre high stalagmite.
• The “Brilliant” – the iconic white calcite column in the cave.

Wildlife: the baby dragons (olms)

Within the cave system is a vivarium where you may see the pink-gilled, blind cave salamander known as the olm. These creatures have captured the imagination of visitors for generations, and are often called baby dragons due to their appearance.

They’re only found in this type of cave system.

The olm is the symbol of Slovenia’s Postojna caves and appears on its merchandise and marketing.

Extra attractions

Depending on your ticket you might also explore:

• EXPO Cave Karst – an interactive exhibition about the formation of the caves and karst processes.
• Adventure tours – for those who want a more challenging caving experience (with helmets, boots, ropes).

Combining with nearby attractions

While the Postojna Caves alone can fill a half or full day, there are excellent options to combine your visit with other nearby sights:

• Predjama Castle: Just a short distance away, this dramatic castle built into a cliff offers a seamless extension of your trip
• Lake Bled: The jewel in Slovenia’s crown. Stunningly beautiful
• Other caves: Slovenia’s karst region is rich in subterranean wonders; if you have time you might explore more of them.

I recommend the tour below, which I did. Others may look cheaper, but don’t include the entry to the caves and castle, which this one does.

Postojna caves, Predjama Castle and Lake Bled in a day. Ideal if your time in Slovenia is limited

Hotels in Postojna

Postojna is a great stopping off point for people who want more time in the area, or are continuing on the Adriatic coast and Slovenian tourist towns like Pula, or on into Italy and Trieste.

Click on the following link for accommodation options in Postojna.

FAQs & insider tips

Is the tour suitable for all ages?

Yes — the standard tour is suitable for most. Children under 14 must be accompanied by an adult. Some of the adventure tours require more physical ability and have age/capability restrictions.

Are Postojna Caves Accessible

Yes, Postojna Caves are accessible and comply with Slovenia’s accessibility laws. The complex features dedicated disabled car parking spots, toilets and wheelchair friendly entrance points. The caves themselves have nonslip flooring and there are no steps. However, there is a fairly steep slope (20%) of about 200m, with a corresponding descent. Wheelchair users will need a support person, and must give 48 hours’ notice to the Cave management.

How long does the tour take?

Typically around 90 minutes for the main guided tour including the underground train ride.

Is photography allowed?

Yes — you’ll be free to take photos. Just remember: no flash may be allowed in some parts (check with your guide) and always follow the rules (e.g., not touching formations).

What about crowds & best timing?

In peak summer months expect more visitors. Aim for an early tour slot or visit in shoulder seasons (spring, autumn) for a slightly quieter experience.

What’s the weather like inside?

As noted earlier, 8-10 °C (46-50 °F) is typical inside Postojna caves. Dress in layers and bring a light jacket or jumper.

Are there food / drink facilities?

Yes — at the entrance area (and park) there are café/restaurant facilities. But once inside the cave system the tour is sealed, so stock up beforehand.

Can I combine with transport easily?

Yes — from Ljubljana it’s quite direct. If you’re using public transport, check schedules for onward return.

Final thoughts – Postojna Caves, Slovenia

Visiting the Postojna Caves in Slovenia isn’t just another tourist stop! It’s an experience that combines geology, history, natural wonder and a sense of discovery. Whether you’re exploring the underground corridors, gliding on the cave train, marvelling at icy white formations, or peering into the world of ancient subterranean creatures — you’re in for something truly memorable.

If you plan carefully (book ahead, dress warmly, pick a less busy tour time) you’ll ensure your visit is seamless, enjoyable and inspiring. And once you emerge into daylight again, you’ll carry with you the memory of an underground realm few places can match.

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