Postojna Cave
Postojna Cave's interior

Postojna Cave, the most visited attraction in Slovenia

This post is also available in: Português

The Postojnska Park Complex, which is composed by the Postojna Cave and the Predjama Castle. It is the most visited place in Slovenia, having almost 1 million tourist annually. This exodus of travellers has a reason: the Postojna Cave is one of the most beautiful things we have ever seen in life.

The cave is about 24 km long, however only 5 of them are 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.

P.S.: The temperature inside the cave is around 10 degrees Celsius, meaning it is very cold! So, don’t forget your coat;

P.S.2: All the pictures are from the marketing department of the Postojnska Jama Park

The train inside Postojna Cave
The train inside Postojna Cave
We visited Postojna Cave during a bike trip from Italy to Slovenia. If you want to know more about our first cycle touring experience, check it out our Facebook, Instagram and Youtube Channel, where we have been posting weekly videos, such as the one below, about Postojna Cave and Predjama Castle.

Why have we liked so much Postojna Cave?

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 Postojna. It 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”.

– You may also like to read: 

One of the galleries inside the Postojna Cave
One of the chambers inside the Postojna Cave

What are stalagmites, stalactites and speleothems?

Just for the record, so to avoid you to jump onto 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.

A column inside Postojna Cave
A column inside Postojna Cave

How are the chambers inside Postojna Cave?

The chambers are named accordingly to its appearance. Amongst them, the most famous are:

  • the Spaghetti Hall, plenty of little thin and fragile stalactites that “fall” from the roof;
Spaghetti Hall inside Postojna Cave
Spaghetti 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;
White Hall inside Postojna Cave
White Hall
  • and the Concert hall, 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!

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

A bridge inside Postojna Cave
One of the bridges that crosses the cave’s interior

What have we NOT liked about Postojna Cave?

The fame of the cave has also its negative side. 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 rail inside Postojna Cave
The rail inside the cave

Why can’t we touch the cave’s interior?

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…

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 fourth of the cave is opened for tourism when the rest is protected and far from the reach of the public.

Postojna Cave
The cave’s interior

Olms, the inhabitants of Postojna

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.

An olm from Postojna Cave
An olm or baby dragon

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.

A female olm with its eggs inside Postojna Cave
A female olm and its eggs

The Predjama Castle

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.

Predjama, which means “in front of the cave” in Slovenian – Pred=in front of; Jama=cave, dates back to the XIII century. 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.

Predjma Casle, next to Postojna Cave
Predjama Castle

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: He dies!

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

A medieval festival in front of Predjama Castle
A medieval festival that happens in front of the castle

How to get to Postojna Cave and Predjama Castle?

Indeed, the best option is by car. You rent one and life will be easier over there. However, if you are depending on public transport, there are a bus stop just by the cave. There are buses coming from Ljubljana, Koper, Nova Gorica, and even Croatia, that stops over there. There is also a train station in Postojna town, where you can take a bus from there to the cave. Surely, however, an easier way is to go on a tour arranged from your hostel/hotel in major cities, such as the ones we have cited above.

The interior of Postojna Cave
The interior of the cave

How to go 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!

Where to sleep and to eat in Postojna Cave?

The whole complex has plenty of restaurants, bars and coffees. Just opposite the entrance of the cave, there is the 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. Another option is the centre of Postojna town, with many hotels and B&Bs.

Hotel Jama close to Postojna Cave
Hotel Jama

Price for the Postojna Cave and Predjama Castle

  • Just the cave: 28,80 Euros
  • Just the castle: 13,80 Euros
  • Cave + castle: 35,70 Euros
  • Cave + night on Jama Hotel: 75,90 Euros

For further information, check it out here.