Caves in Slovenia

Enter the magical underworld of the Karst and visit the most beautiful caves in Slovenia. You probably heard about the world-famous Postojna Cave, which is a must-see for everyone visiting Slovenia and equally breathtaking Škocjan Cave, featured in the UNESCO World Heritage List since 1986. But there are numerous other underground mysteries in Slovenia waiting to be discovered. Continue reading to find out about countless karstic wonders, the dragons living in the Slovenian underworld and the exciting underground train and boat tours you can take while visiting this tiny country in the heart of Europe.


The majority of caves in Slovenia can be found on the Karst Plateau (Kras in Slovene), a region in the southeast of the country. It is characterized by a limestone-based landscape full of extraordinary features such are caves, sinkholes and karstic fields. It was here the karst phenomena were scientifically described for the first time and gave its name to similar landscapes found throughout the world.

How does it work? The foundation of the Karst Plateau is limestone, a soft rock which is soluble in water. Rain and streams flowing over its surface over millions of years have shaped the rocky landscape and created a huge variety of formations, most impressing being the underground cave systems.

Caves in Slovenia: Postojna


Check out the most beautiful caves in Slovenia


At this point, there are over ten thousand registered karstic caves in Slovenia. Each year explorers locate additional 100 caves and scientists believe there are another twenty thousand caves out there just waiting to be discovered. This is just an astonishing number for a country of just over 20 thousands square kilometers. However, only 21 karstic caves in Slovenia are open for tourist visits. Here is a brief list of those you should definitely consider peeking into.


The world-famous Postojna Cave is the largest cave system in Europe open to public. It has been carved out by the Pivka River which runs through it and features jaw-dropping stalagmites and stalactites which have been impressing its visitors since the 19th century.

The oldest written records of Postojna Cave date back to the 17th century, but the graffiti found inside suggest, that humankind has been aware of its existence for hundreds of years before. Reports of its beauty found its way to the Austro-Hungarian nobility in Vienna who wanted to see it for themselves and thus kick-started the tourism in Postojna Cave.

It is over 24 kilometers long, therefore it is impossible to walk it all in one go. For convenience of the visitors, train rails were laid in 1872 and electric lighting was added in 1884 (preceding even Ljubljana). The 2-hour tour through the most impressive parts of Postojna Cave is regarded as one of the highlight of Slovenia and is featured in most of our itineraries.

Postojna Cave in Slovenia

MORE CAVES AROUND POSTOJNA: You should note that the whole Postojna Cave System includes four other caves, which are actually its natural entrances. They were all carved out by the same river (Pivka) and are worth visiting on their own, especially if you are speleologist or a big underworld enthusiast.

 Pivka Cave is about five kilometers long, but only two are open to public. The cave can be accessed by following 317 steps through a collapsed shaft which goes 65 meters deep. Once down, the guided tour follow the Pivka River and later enters the adjusted Black Cave through the artificial 100 meters-long passage. This 3.3-kilometre-long cave boasts large halls and horizontal passages, as well as dark speleothems, which gave the cave its name. Adrenaline lovers can visit Pivka and Black Caves in a commination with Postojna Cave. Bare in mind that you will need to pre-book this tour and you better show up in hiking equipment as the path features more difficult passages and water barriers. Contact us for more details.

Otok Cave is a dry horizontal cave with an abundance of stalactites and stalagmites. The 45-mintue guided tour is done is small groups and is only possible if booked in advance. Due to its unique beauty, Otok Cave has served as a filming location for a number of feature films.

 Magdalena Cave is the last discovered cave within the Postojna Cave System. Although a small cave, it is extremely rich in formations, landscape and wildlife. Visiting this by all means spectacular beauty is only reserved for experienced cave explorers and there are no regular tourist visits.

 Planina Cave is not part of the vast Postojna Cave System but we should mention it nonetheless, due to its proximity. Furthermore, the river Pivka which carved the Postojna cave system also flows through Planina Cave where it merges with Rak River, creating one of the largest confluences of underground rivers in Europe. Book a boat tour for a truly unique experience.

Skocjan Cave in Slovenia


Most visitors to Slovenia decide to visit Postojna and doesn’t see the need to enter another underworld system. We encourage you think again, since the Škocjan Cave is a completely different story. It is in fact an underground canyon carved out by the Reka River and acknowledged as an exceptional karstic phenomena by international scientific circles. In 1986 the Škocjan Cave has been added to the UNESCO World Heritage List as an extraordinary natural feature, confirming its place among the most important caves in the world.

Similar to Postojna Cave, tourism in Škocjan Cave begun in the early 19th century when the steps into the great underground collapsed valley were constructed. We know that the visitors’ book was first introduced on New Year’s day of 1819, marking the beginning of modern tourism. Nowadays the Škocjan Cave welcomes approximately 100,000 tourists per year, who usually combine their visit with the nearby Lipica Stud Farm, another gem on Slovenia’s itinerary.


Explore the magical underworld of Slovenia


KRIŽNA CAVE in the Lož Valley is a karstic cave most notable for the string of more than 45 subterranean lakes, which make it perfect for exploring on foot and in a boat. A popular 1-hour excursion also includes a display of numerous cave bear bones found here. It is also worth noting that Križna Cave is the fourth-largest cave ecosystem in the world in terms of biodiversity, as 45 different organisms were discovered here, some not until 2000.

The cave was first documented in 1832, but the part of the cave that includes the gorgeous emerald lakes and stream passages was first explored almost a century later.

Caves in Slovenia - Krizna

Predjama Castle & Cave

PREDJAMA CAVE represents a significant part of the Predjama Castle, one of the most visited castles in Slovenia perched in the middle of a 123-meter-high rocky cliff. It tells a story of the rebellious knight Erazem, who withstood the imperial army’s siege by using the secret tunnel which connects the castle with a vast 14-kilomters-long cave system in the background. The whole system – also home to a colony of bats – spans in four floors and can only be explored on a special adrenaline tour booked in advance; while the 700 meters of its most interesting parts can be visited with a special extended castle ticket. Let us book the right tour for the desired level of adrenaline.


You still don’t have enough? There are many other caves in Slovenia just waiting to be explored. Let us list some less visited, but equally charming gems of the Slovenian underworld:

Kostanjevica Cave is set in the region of Dolenjska, at the foot of the Gorjanci Hills, near the charming town of Kostanjevica na Krki. The tour of this relatively small cave includes 300 meters of its most beautiful part full of elegant stalactites and stalagmites.

Vilenica Cave is notable for hosting the annual Vilenica International Literary Festival. It’s Dance hall is simply a perfect venue and the mystical colors of numerous stalactites and stalagmites create a truly unique atmosphere. Of course you can visit the cave all year round.

Divača Cave is a less known karst beauty in the close proximity of the Škocjan Cave. It was carved out by the same river (Reka) and welcomes tourists from the beginning of 19th century. Among its most famous visitors were the Austro-Hungarian crown prince Rudolph and Sigmund Freud.

Dimnica Cave is about 8 kilometers long with passages on two levels. The upper one is dry and allows visitors to mingle with its beautiful dripstones; while the lower passage is filled with underground stream.

Snow Cave is the highest lying tourist cave in Slovenia (1554 m), located under Mt Raduha in Gorenjska region. This unique cave features a combination of elegant stalagmites and ice sculptures, hence the name. You can only visit the cave accompanied by a guide.

Not far away from Tolmin, by the entrance to Triglav National Park, lies the infamous Dante’s Cave, named after the legendary Italian poet who visited this area back in the 14th century. Its depths supposedly served him as an inspiration when describing hell in his world-famous masterpiece The Divine Comedy. However inviting this might sound, this over-a-kilometer-deep cave proves very difficult to explore without a licensed guide and proper equipment.

Županova jama translates to Slovene as Mayor’s Cave in the memory of Šentjur’s mayor, Josip Perme, who discovered it back in 1926. It is worth noting that a few scenes from one of the Winnetou movies were filmed here.

Pekel means hell in Slovenian, but there is nothing hellish about this gorgeous karst cave in  the Lower Savinja Valley. It was only named this way because of the image of the devil above the cave’s entrance. But you will need some imagination to see it.


The karst caves of Slovenia and also Croatia are wonderful creations on their own, but they wouldn’t be as perfect without their special inhabitant – proteus or olm. Centuries ago people used to believe these little reptiles are actually dragon offspring, which shouldn’t come as a surprise since the dynamic underworld of the Karst region has always been stirring up our imagination. A whole bunch of creatures were believed to live in the caves of the Dinaric world, including elves and dwarfs. Since most of them are just products of our mind, olms are very, very real. And you can meet these little fellas in Postojna Cave, the most popular attraction in Slovenia.

Because their skin color resembles the one of the white people, they are very often called “The Human Fish”, especially by the locals. Bear in mind they are neither fish nor dragons, but very shy aquatic salamanders and don’t really like daylight or noise. Due to its adaptation to the cave habitat, proteus is completely blind and has no pigmentation. Instead it developed good smelling and hearing senses, so try not to make any loud sound while observing them. They are very vulnerable and any change in climate can harm them. Olm is now included in the Slovenian red list of endangered species, not just because of the environmental issues, but also due to collectors taking these animals from their natural habitat.

Proteus, olm, human fish, Slovenia

Even if you are not a speleologist, you will love exploring the magical caves in Slovenia. The most famous ones (Postojna and Škocjan) are typically included in more or less every itinerary, but since we like to brag about being local experts and tailor-made itineraries being our specialty, there are no problems including even more caves to your personalized tour of Slovenia.

Contact us at and let our agents know that you are a big underworld enthusiast. We will try to accommodate your wishes and balance them with your physical fitness, time constraints and budget.


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