Škocjanske Jame / The Škocjan Caves

A subterranean wonder world

Tu pride flash

The Škocjan Caves acquired their name from the nearby village Škocjan, which was named for St. Kanzian, the patron saint of Aquilea (Oglej). Villages named Škocjan were commonly established close to water or springs. Here also the Reka River pours through the extraordinary underground gorge, held by experts to be the largest underground river in the world. The place where the Inner Carniolan Reka River finally disappears underground is called Reški rov (Reka Passage), although this is only one of the openings between the first sinkhole of Reka and the mighty landslide Dolina in its hinterland.

The so-called karstic phenomena, which are in Slovenia associated with the Karst region (Kras in Sl.), also distinguish the environs of Škocjan Caves, and actually all those regions on our planet, where limestone is prevalent. The word kras is of Indo-European origin, originating in the word “kar”, “kamen”(stone) or “karras”, that is a stony place. In such regions there are usually no running waters, but if they do appear they tend to suddenly disappear underground and reappear again, sometimes as mighty water courses. On the surface the most frequent karst phenomena are bowl shaped, from “škraplje” to “vrtače” in their thousands, the larger “uvale” and still larger karst flood fields. On the 100 km long road from Trieste (Trst) to Ljubljana, three great and unique karst landmarks have been known since the antiquity: the Škocjan Caves, the Postojna Cave and the Cerknica Lake.

It must by said by the way of introduction that the Škocjan Caves are quite different from the Postojna Cave. The Postojna Cave is embellished with all the decoration that nature is able to provide, but the river itself left it, so that it is a lifeless or dead cave. The Škocjan Caves on the other hand, are very much alive due to the underground Reka River, which displays with its grand spaces the shaping power of water. By the way of introduction we may point out that according to the most recent measurements the length of all the caves in Slovenia comes to c.730 km, which is considerably more than the length of all the roads of Slovenia. That is why it is no wonder that Slovenia takes pride in the oldest and largest centre for the study of karst in Postojna, The Institute for Kras Research ZRC SAZU.

The creation of Caves of Škocjan

The area of karst proper, that is the landscape in the hinterland of Trieste is composed of sea sediments, which were deposited in lime forming sea during the  “cretaceous epoch,”, between 140 and 65 million years. On more than 1000 m thick layer of pure limestones, later during a period of eight years deposited a further 400 m paleocene limestones, and on top of them another 600 m thick of layer of flysch sequences from the eocene epoch. When the sea retreated, the usual river network without karst phenomena was formed on the impermeable flysch. These phenomena began to form some time later, when the river erosion together with the so-called alpine wrinkling, uncovered after millions of years eocene flysch. In addition the Dinarids also began to rise about two million years ago. Where the impermeable flysch was carried away, the waters began to seep into cracked and porous limestone. At the start of the ice age the karst phenomena were developed in full measure, and the Reka River began along the network of passages, its underground course towards the Gulf of Trieste.

Here it should be mentioned, that the Reka River basin is constantly diminishing and so does the underground water stream within the Škocjan Caves. Water begins to seep away in its riverbed some 10 km before reaching the major sinkhole, one of the reasons for dozens of mills ceasing to operate during the last century. About 1,000 years ago Reka disappeared underground in sinkholes 5 km west of the present day entrances, and when waters were high, extensive areas of the region were flooded regularly. The ponor (sinkhole system) of Reka River was actually constantly moving, withdrawing and advancing on its search for new routes, while at the same time beginning to hollow out large spaces in the limestone. In the process great landslides occurred In the thin ceiling, and giant landslip valleys emerged. In some places entrances remained open, elsewhere they filled up, and new ones appeared.

Discovery and exploration of the Škocjan Caves

Mighty entrances into the Škocjan Caves were already described by J.V. Valvasor in his work The Glory of the Duchy of Carniola, but he apparently did not quite dare to enter and explore further. However the local people did undertake some exploration of the caves and found in landslip entrances safe shelter and drinkable water. With these local guides other intrepid travelers and visitors allowed themselves to be lowered into the mysterious and romantic cauldron, Velika Dolina (Big Valley). They also entered the side opening leading into the passage behind the first sinkhole of Reka, which flows under the village Škocjan into what is today Mohorčičeva jama (Mohorčič Cave). Here began the first amateur exploration of Škocjan Caves. The Triestine Jože Eggenhoffner swam the 200 m long passage beneath the Škocjan village. The local men also became keen on underground exploration, particularly the district mayor Jože Mohorčič (1763 -1831), for whom one of the caves was named. On 1.1.1819 he established a special visitors book, a few years ahead of the Postojna Cave.

On the initiative of the district governor Tominc a safe trail into Velika Dolina was completed, reaching as far as the dry, some hundreds metres long, stalactite cave in its northern wall, today Tominčeva jama (Tominc Cave), which had been discovered earlier. On the initiative of Eggenhöffner, Jakob Svetina (1802-1872), a master plumber from Trieste, joined in the exploration of the Škocjan Caves. In 1839 he was the first to explore Velika Jama (Big Cave) by boat, the last sinkhole in Velika Dolina. He penetrated only some 120 m downstream, as far as the third cascade. However, the passage was so narrow, that he could not pass through. His idea had been actually to find a water source for the Trieste water distribution system.

The most renowned karstologist, speleologist and geographer at the time, Adolf Schmidl of Vienna, also involved himself intensively in the exploration of Škocjan Caves. With the assistance of the mining engineer Ivan Rudolf and four miners from Idrija, he penetrated to the Sixth Cascade, that is some 300 m further than Svetina. Sudden high water carried away all their equipment and prevented further exploration. He named the first part of the Škocjan system after the mayor Mohorčič, and proceeded to investigate other, friendlier caves.

In 1879 the first speleological association in the world was established in Vienna, Verein für Höhlenkunde. A member of the association, Viljem Putick, later settled in Ljubljana, and was one of the founders of the Association for Exploration of Caves in Ljubljana in 1910.

From the beginning a group of local farmers, who risked their lives no less than the intrepid explorers, participated In the exploration of caves. It was these local men who laid and improved the first precarious trails, one was even named Mačja pot (Cat Trail). Without them the learned men would not have got very far. The modest payment, that the brothers Cerkvenik, brothers Antončič, Jože Nedoh, Franc Cerkvenik and others for their efforts and courage was small thanks for the work they did, nevertheless it did contribute vitally towards the upkeep of their families. 

Members of the German-Austrian Mountain Association in Trieste were on the other hand well-to-do townsmen and nobility, also high-ranking public servants and merchants, who liked to make contributions towards explorations, building of trails and managing tourist visits.

In the year 1880 the Czech Anton Hanke moved to Trieste, and became one of the most intrepid explorers of Škocjan Caves, but unfortunately did not live to witness the conclusion of the exploration. The Trieste merchant Jože Marinič worked closely with Hanke. The brothers Heinrich and Friedrich Müller and the Czech Josef Novak should also be mentioned. After 1905 there were no new discoveries in the caves, and the locals continued to provide a regular guide service through the accessible areas of the Škocjan Caves.

After World War I Škocjan Caves came under the authority of the Italian Societa Alpina delle Giulie, and the existing names were replaced by Italian names. Under the new Italian authority several existing tourist trails were extended and some sturdy bridges were built. Accordingly tourist numbers increased, partly due also to increased promotion. After World War II most of the Kras region became part of Yugoslavia. Neglected tourist approaches were upgraded and in 1959 electric lighting was installed in the tourist section of the cave. The cave continued to receive a modest 5000 visitors annually. This changed on 28 November 1986, when UNESCO included Škocjan Caves  on the world heritage list. With the opening of the reception centre and installation of the comfortable lift from Velika Dolina, the number of visitors began to grow, reaching the number 70,000 by 1998. Among the many celebrities visiting Škocjan Caves was the world famous psychiatrist Sigmund Freud. 

A more detailed description of the Škocjan Caves.

The Škocjan Caves fall into three principal parts: 1. Male jame (Little Caves), the underground passage underneath the settlement Škocjan; 2. the landslide Dolina (Valley) cave system, and 3. Velike jame (Big Caves), the system of underground passages west of Dolina landslide.

The first part consists of the Mohorčič Cave and Marinčič Cave, it is the underground passage underneath the mighty 250 m long natural bridge. When the water is at its highest, the Reka River current here reaches the velocity of as much as 150 m per second. The river flows over picturesque cascades and lakes, and appears above ground at the bottom of the landslip Mala Dolina. In ancient times, before the thin limestone roof cracked and fell its to the bottom as rubble, this had been as an enormous underground cave.

The second part of the Škocjan Caves system is Dolina (Valley), the most picturesque and precipitous sinkhole or basin. A natural ridge divides it somewhere along the middle into Mala Dolina in the east and larger Velika Dolina in the west. In the bottom below, the Reka River tumbles over the rapids, on the rock faces there are many entrances to the underground caves. The locals have named the natural window, shaped like a giant lock “Miklov Skedenj” (Miklov Barn). Velika Dolina also has many entrances into the underground passages, but archeologically the most significant are Tominčeva jama (Tominc Cave) and higher up, the hidden Ozka Špilja (Narrow Cave). Tominčeva jama is over 200 m long and was till 1885 the only real tourist part of Škocjan Caves. In layers near the entrance into the passage they found many very ancient objects, from the mezolithic and neolithic periods right up to the Middle Ages. It is quite possible that the cave had served as a Christian sanctuary. There is evidence that local people took refuge in the cave at the time of Turkish incursions. Unfortunately the great wealth of archeological finds have been scattered among museums from Padua to Trieste and Vienna.

The third part of Škocjan Caves is the system of the underground river, where Reka finally  disappears into Reški rov (Reka passage), at 270 m above sea level. Reka surges along the Rudolf dvorana (Rudolf Hall) over three waterfalls , and through a narrow passage into the mighty underground 300 m long, 100 m high and 50 to 80 m wide canyon of Svetina Hall and Müller Hall. The first poorly equipped explorers experienced this part of the cave  as truly intimidating and hazardous. Schmidl despaired at the Sixth Cascade where the cave narrows again. This obstacle was overcome only in 1884, when the first explorers were already daring enough to have themselves be let down into 300 m long Hanke Canal. The bridge over this canal, according to the plan by Franc Cerkvenik from the village Matavun, was built only in 1937, and is named after the creator Cerkvenikov Most (Cerkvenik Bridge). Later they also began to explore the upper passages and it was only in 1904 was opened the entrance 50 m above Reka, into 630 m long dry cave Tiha jama (Silent Cave), displaying stalactites and stalagmites. The cave is a kind of a blind sleeve without running water. Tiha jama was barely accessible for the tourists till 1938, when they opened a short tunnel from the valley Globočak.

Cerkvenikov most is the last vantage point, where the average tourist can observe the subterranean river, which disappears from view at this stage. The cave ends after 1 km and a half. In the beginning of the 20th century a cut was made into the right bank of the underground gorge to form a fairly wild path, reminiscent of mountain trails.  Different sections of this part of the cave system have each been given their own name. After the 24th cascade the gigantic canyon descends to the Martelovo Jezero (Martel Lake), with the ceiling so low, that it can be crossed only at low water. Then follows the 100 m long Marchesettijev Rov (Marchesetti Passage), and the last siphon. Through the 100 m long Obhodni Rov (Circuit Passage) it is possible to reach the dead siphon, that is Mrtvo Jezero (Dead Lake). From this point, where Reka finally disappears into Velika Luknja (Big Hole) beneath Škocjan, and the entrance to the Mohorčič Jama, to its reappearance as the river Timava, the distance is about 30 km.

The whole river basin of Reka, with the 1796 m high Snežnik Mountain rising above, comprises in its entirety 450 km 2. The Snežnik plateau is crossed by the ridgeline. On one side the waters stream into the river Pivka and flow towards the Black Sea, on the other they flow into the Reka River and the Adriatic Sea, only 20 km away. Here the influence of the Mediterranean is fairly evident and can be seen in plant and animal varieties that live here (wolf, lynx, some rare bird varieties).

The protected area of Škocjan Caves with the Reka River gorge and the surrounding cave systems comprises an area of 413 hectares. In 1986 the Škocjan Caves Park was listed by UNESCO as a site of unique cultural and natural world heritage. Albin Debevc, director of the Škocjan Caves Park at the time succeeded in convincing (n Spanish language) the Commission in Barcelona  that Škocjan Caves are a unique natural creation. Beside the caves on the border between Slovakia and Hungary, Mamut Caves and Carlsbad Caves in USA, they are the only caves on the Index of World Heritage. The Škocjan Caves are also included in the Ramsar Convention, as the first underground “mokrišče” (underground wetland) in the world. The natural habitat of Škocjan Caves includes highly  specialised and some endemic varieties of water and land cave animals.

The region of Škocjan Caves has been settled since the Stone Age. Roman authors Pliny and Strabo mention a settlement in this space 2000 years ago. Archeologists however, discovered even older pre-historic fort (gradišče or kaštel). The richest archeological finds were discovered underneath the village Brežec at the turn of the 19th into the 20th century. The necropolis of Brežec from the period between the 10th and 7th centuries BC is well known for the great number of weapons and ornaments found there. Archeologists discovered twenty pre-historic archeological sites in the area: settlements, burial grounds,  and cult caves. The best known is Velika jama or Mušja jama on Prevala, which is a unique archeological waste disposal cave site in Slovenia. In 1910-1911 the imperial archeologists from Vienna discovered hundreds of objects and of course took them away to Vienna or Trieste. It might also be mentioned that Škocjan Caves have been marked on the oldest printed maps of the region, for example on Kazius’ chart of 1573.

For the first time since the count has been taken in 1884, the number of visitors exceeded 100,000 in 2008. Still not as many as the visitors of Postojna Cave or Lipica. The number of visitors began to grow from 1996, when the Škocjan Caves Park was established in 1996, when the visitors numbered 45,000. At present resources are being put into infrastructure and upgrading, with funds also provided by EU. Since Škocjan Caves are spaces of exceptional dimensions, it is fairly clear that many kilometers of trails and five bridges have to be constantly upgraded. The upgraded lift, now accommodates 40 visitors. Organized viewing of Škocjan Caves usually takes one hour and a half, and is an unforgettable experience.

In Matavur a Promotional Congress Centre has been established, in the renovated Delezov Homestead.

In the Natural Science Centre of the Škocjan Caves Park a collection of stones and fossils from the  “cretaceous epoch,” and a biological and archeological collection are on display.

Translated by Aleksandra Ceferin


Svetovna dediščina v Jugoslaviji, UNESCO, Naravne in kulturne znamenitosti, Založba Mladinska knjiga, Ljubljana, 1990;

Borut Mencinger: Naravni parki Slovenije, Mladinska knjiga Založba, 2004;

Dušan Grča, Delo.