Postojna Cave and Predjama Castle – the best of Slovenia tourist attractions

A large stalagmite inside Postojna Cave and other stalactites and a couple observing them

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The Postojnska Park Complex is composed by the Postojna Cave and the Predjama Castle. They are one of the best of Slovenia tourist attractions, having almost 1 million tourist annually. This number does not really surprise us because the Postojna Cave is one of the most beautiful things we have ever seen in life. And the Predjama Castle has a such awesome story as well.

By the way, we have a complete guide of what to do in Slovenia, explaining how to get around, the nature, the cities, itineraries, activities and much more. Have a look on that too!

Postojna Cave and Predjama Castle Index


a train on a trail inside Postojna Cave with people in it
The train inside Postojna Cave – Photo: Postojnska Jama Park

How to get to Postojna Cave

There are essentially three ways of getting to Postojna Cave and the Predjama Castle (they are located within the same complex, 9km apart from each other):

  • You can drive there: Postojna Cave is located 50km from Ljubljana via the A1 motorway. Going by car to Postojna Cave from Ljubljana is probably the easiest way. You can also reach it by the A1 motorway from Koper or Trieste (Postojna motorway exit No. 41, which is 2km from the entrance).
  • You can take public transportation: there is a bus stop just by the cave. There are buses coming from Ljubljana, Koper or Nova Gorica that stops over there (check buses timetable here). There is also a train station in Postojna town, where you can take a bus from there to the cave.
  • Or you can take a guided tour leaving from Ljubljana, Trieste or even Croatia. This can be very convenient if you don’t drive as you will be picked up and dropped off from your hotel (tours costs average U$ 80 with everything included – have a look here).

* If you are planning a road trip in Slovenia, make sure to make a quotation at Rental Cars, which in our opinion is the best and most affordable car rental search engine.

A sign writen Skocjanske Jame and Matavun, which is the directions for Postojna Cave in Slovenia

How much is the tickets for Postojna Cave and Predjama Castle

  • Just the cave: 28,50 Euros
  • Just the castle: 17,50 Euros
  • Cave + castle: 40,90 Euros

You also have the chance to visit the vivarium and the Expo Cave Karst. The Vivarium is the research laboratory for the olms. The Expo Cave Karst is an interactive exhibition on events that resulted in the cave. Both single tickets is 10,90 Euros.

  • Cave + Vivarium+ Expo Cave Karst: 39,90 Euros
  • Full Park Experience (All of the above): 49,50 Euros

For further information, check it out here.

How is the Postojna Cave tour

The cave is about 24 km long. However, only 5km of them is opened to the public. The nicest part is that 3,5 km is done by train! That’s right, this is the only cave in the world with a train to take its visitors around its interior. The remaining 1,5 km you do by foot and with a guide. The whole tour takes about 1 hour and half.

Just bear in mind that the temperature of inside the cave is around 10 degrees Celsius, which means is very cold! So, don’t forget your coat!

A large stalagmite inside Postojna Cave and other stalactites and a couple observing them

That wasn’t our first cave. In fact, we have visited quite a few during our travels, such as the Cango Cave in South Africa and Ali Sadre Cave in Iran. However, none of them were as majestic as the Postojna Cave.

The cave is divided in many chambers, galleries and passage ways, and each of them are unique. Its uniqueness are due to the difference in age, sizes, colours and shapes of the stalagmites, stalactite and speleothems – the latter also known as “curtains”. It is surely a totally worth visiting activity in Slovenia – probably one of the best!

What are stalagmites, stalactites and speleothems?

Inside Postjna Cave with two stalagmites and stalactities almost touching each other

Ok, no need to switch to Google right now. Stalagmites are those columns inside a cave that grow from bottom up. On the other hand, stalactites are the columns that grow from the ceiling down. Once they touch each other, they are known as columns. The speleothems are another type of formation which remind us of a curtain, as it is thin, wavy and long in length, not necessarily in height.

How are the chambers inside Postojna Cave (what to expect from your visit!)

The chambers of Postojna Cave in Slovenia are named accordingly to its appearance. The most famous chambers inside the cave Postojna are:

Spaghetti Hall

A large hall known as spaghetti hall inside Postojna cave with many rock formations small and thin hanging from the ceiling
Spaghetti Hall

The Spaghetti Hall, plenty of little thin and fragile stalactites hanging from the roof.

White Hall

The large white hall inside Postojna Cave with a gigantic rock formation near where people pass
White Hall

The White Hall, all very white from the excess of limestones and also where it is the most famous stalagmite known as “Brilliant”. It has 5 meters high and it has already become a symbol of Slovenia.

Concert Hall

Concert hall is the largest of all where it holds classic music concerts during the end of year festive holidays as well as other events. How cool would be to see a concert inside a cave?!


These are just to name a few of the many galleries, but they have a lot more, one more beautiful and surreal than the other – just remember that there are 5km to explore inside Slovenia’s Postojna Cave!

What is the Postojna Cave and how it was formed?

A bridge connecting two rocks where people walk inside the Postojna Cave
One of the bridges that crosses the cave’s interior

The Postojna cave was “shaped” by the Pivka River. This river goes through the Slovenian subsoil until it meets with another river and breaks through the surface once again, this time as Unica River.

We visited Postojna Cave during a bike trip from Italy to Slovenia. Check the video of when we arrived in the Postojna Cave and Predjama Castle in Slovenia:

What not to do in Postojna Cave

The number of tourists that visit the attraction is really high and is hard to control them all. For instance, our group had about 50 people for one guide only and, despite the numerous pleas from the guide not to touch anything, people insisted in touching absolutely all stalagmites and stalactites they saw.

The path for tourist through the Postojna Cave

Our skin has a bacteria that, when it gets in touch with the surface of the cave, it inhibits its formation. One stalactite takes about 30 years to grow 1mm. Just to barely touch is enough to destroy the whole process. Therefore, imagine the size of the negative impact in this environment due to the lack of care by its visitors. That’s the reason we cannot touch the cave’s rock formations.

Inside Postojna Cave with a little lake reflecting the cave and the passage for the tour

We spoke with many people about that. After all, Slovenia is proud of holding the title “The most sustainable country in Europe”. But this episode upset us dearly. What we heard from everybody is that just 1/4 of the cave is opened for tourism when the rest is protected and far from the reach of the public.

Olms, the inhabitants of Postojna Cave

The Proteus baby dragon salamader inside Postojna Cave
An olm – or “baby dragon”

The Olms are a kind of an albino blind pre-historic salamander living in the interior of the cave. They can live for up to 100 years, reach up to 25cm in length and survive up to 10 years without being fed – kind of the perfect pet for travellers ;). In a long time from now, people thought they were babies of dragons. It’s a name carried to our days as they are still known as Baby Dragons. However, their original name is Proteus Anguinus.

Proteus the cave salamander inside Postojna Cave
A female olm and its eggs

In 2016, a female laid 50 eggs, which 22 gave birth. Yeeey! This fact impressed the Slovenians and the international community as the Olms reproduce every 10 years and, never before, this process had been observed by specialists.

At the end of the tour, there is an aquarium where you can see some of the baby drag…we mean, cave salamanders. Once again, despite the numerous pleas by our guide not to use light towards these animals – they are sensitive to light, people have not hesitated in flash their mobile lanterns to record, take pictures and see them better.

The Predjama Castle

Aerial view of the Predjama castle complex

If you are visiting the Postojna Cave, DO NOT miss on the Predjama Castle! Seriously, this is the most fascinating castle we have ever seen. It was built within a 123 meters high rock and it is the only castle in the world of this kind.

Some people might also know it as Postojna Castle, but it is not. Predjama means “in front of the cave” in Slovenian – Pred=in front of; Jama=cave. The Predjama castle dates back to the XIII century.

The whole idea of the construction of this castle is that, although it lacks in comfortability to its – previous – residents, it makes up for security, which was far more important during the Middle Ages. There are many myths which surrounds Predjama Castle. You can find out about them during the tour, which an audio guide is provided at the entrance.

The Predjama castle cave in a large rock in Slovenia

The most interesting though, is of a prince who was sieged by the Holy Roman Emperor for over a year. No one from the Roman Army could penetrate the castle to capture him. And the prince could obtain supplies for the residents (other families, servants, etc…) through hidden tunnels below the castle. The end of this story we leave for you to discover when you visit the place! But, as today we have Google, the biggest spoiler on earth, we will give the spoiler ourselves right now:

[toggle title=”Click here to know what happens to the prince”]He dies![/toggle]

Below the castle, there is also a cave, which is said to be incredibly beautiful. As it is a place for hibernation of bats, its entrance are opened from May to September only, during the warmer months.

Get from Postojna Cave to Predjama Castle

The two attractions are about 9km away from each other. There is a transfer, but (always a but…) it is only available during the high season – July and August. The other months, you will have to manage on your own. Order a cab or go by bike, just like us!

Fernanda in the window of Predjama Castle overlooking the Postojna Cave complex
View from the Predjama Castle

As we were cycling through Slovenia we managed to camp just near by – as you can see from our video above. It was awesome! And what made the night even better was to be connected with internet all the time. For that, we used Travelers Wifi, a portable wifi that works in more than 50 countries. If interested, we made a whole review on Travelers Wifi.

Where to sleep in Postojna Cave

Night view of the entrance of the Postojnska Jama hotel near Postojna Cave and Predjama Castle

Just opposite the entrance of the cave, there is the Postojna Jama Hotel. It’s a luxurious hotel with daily packages combined with the entrance to the cave and castle – quite worth checking, by the way. You will easily find places to eat as well, as the whole complex has plenty of restaurants, bars and coffees. Otherwise, you can stay and eat in the centre of Postojna town, with many hotels and B&Bs.

If you stay in the Postojnska Jama Hotel, you will get discount on the entrance fees of Postojna Cave and Predjama Castle! Find the rates for the Postojnska Jama Hotel here.

Find out other options to sleep in Postojna town in this link.

*This Postojna Cave and Predjama Castle in Slovenia tour guide post was originally written in 2017 and updated in 2022.