Natural World Heritage - the Dobšinská Ice Cave

National nature monument

Dobšinská Ice Cave – World Natural Heritage

Pavel Bella

The 24th session of the World Heritage Committee in Australian Cairns in November 2000 approved the extension of the WH site “Caves of the Slovak and Aggtelek Karst” (approved in Berlin in 1995) by the Dobšinská Ice Cave.

Dobšinská Ice Cave (Show caves - Dobšinská Ice Cave) is located in the Slovak Paradise in the Spiš-Gemer karst, which belongs among the most important karst territories in the central Europe. It lies in the territory of the Slovak Paradise National Park. The cave entrance, on the northern slope of the Duča hill, is situated at the elevation of 969 m above the sea level.

The cave is formed in the Middle Triassic light Steinalm and Wetterstein limestones of the Stratená Nappe. The spaces consist of three developmental levels. They were modelled by the paleoflow of Hnilec, with waters penetrating along the tectonic faults and interbed surfaces of limestones. During the period of active river modelling the creation of the cave was connected with the development of the Stratenská Cave together forming one united cave at that time. The cave spaces were interrupted later by collapses in the Duča overfall.

The main part of the cave is a great cavity descending downwards to 70m’s depth (the total vertical span is 112 m), which was formed by breakdown of rock pillars between upper and lower developmental levels. The major part is filled with ice, sometimes to the ceiling, which divides it to separate parts (Great and Small Hall, Ruffíny’s Corridor and Ground Floor). Partially glaciated is the Collapsed Dome that reaches under the Duča overfall. Original oval shapes of river modelling are almost entirely destructed by collapses and frost weathering. However, they were formed in the upper parts without ice (Dripstone and White Hall, northern Corridor). The lower part contains non-glaciated Dry Dome and Dripstone Cellar. There are also stalagmites, stalaktites and other forms in non-glaciated parts.

Conditions for glaciation arose probably in the middle Quaternary period after the breakdown of ceilings between the Dobšinská Ice Cave and Stratenská Cave, by which the cave obtained sack-like character with stagnation of cold air that penetrated into the cave through the upper opening formed by collapse of the ceiling part (present entrance to cave). Freezing the percolating rainfall waters caused glaciation of the underground space. The beginnings of ice formation go back to the Riss ice age (approx. 300- to 140-thousand years ago), or until the end of the Mindel ice age. Ice fill occurs in the form of floor ice, icefalls, ice stalagmites and columns. Glaciated surface has 9,772 m2, ice volume reaches 110,132 m3. The highest thickness of ice is in the Great Hall with 26.5 m. The floor ice is characterized by its stratification. The decrease of ice takes place by melting on the contact with the bedrock. Continuous replacement of the underground glacier supposedly takes around 1,700 up to 2,000 years. The ice is slowly moving from the entrance, Small and Great Hall towards the Ground Floor and Ruffiny’s Corridor (2 to 4 cm a year).

The Dobšinská Ice Cave belongs among the most significant ice caves in the world, which is accentuated by its location outside the Alps high-mountain region (underground ice is at elevation of 920 to 950 m above sea). Romanian Scarisoara Cave in the Eastern Carpathians is at elevation of 1150 m. The most important caves with ice in the Austrian Alps are located in higher or high-mountain locations. Cave entrances to Rieseneishöhle are at 1,420 and 1,450 m, the entrance to Eisriesenwelt is at elevation of 1650 m.

Average annual temperature of air in the glaciated Great Hall is -3,9 to +0,2 °C, relative humidity 75 to 90 %. The temperature in the bottom parts of the cave remains under the freezing point all the year round. Air temperature in the non-glaciated parts of the cave fluctuates between +0.8 and +3.5 °C, relative humidity between 85 and 98 %.

The cave stands for the most important wintering place of the Whiskered Bat (Myotis mystacinus) and Brandt’s Bat (Myotis brandtii) in the central Europe. Other bats are represented by the Greater Mouse-Eared Bat (Myotis myotis), Lesser Mouse-Eared Bat (Myotis blythi), Northern Bat (Eptesicus nilssoni) and brown long-eared bat (Plecotus auritus). Twelve bat species were found in the cave by now. The springtail Hypogastrura crassaegranulata dobsinensis is described from the invertebrates. 

Dobšinská Ice Cave is known by a rich history, which corresponds with considerable interest in this unique cave from it discovery. Though the opening to the cave called “ice hole” was known since long time ago, it was only E. Ruffíni accompanied by G. Lang, A. Mega and F. Fehér who descended underground in 1870. Thanks to the Dobšiná town, the cave was opened for the public as early as 1871. Experiments with electric lighting began in 1881. Lighting with Bunsen burners was introduced in 1882 and regular electric lighting started in 1887. The cave belongs among the first electrically illuminated caves in the world. A cultivated mountain park was established along the access way to the cave in 1878.

The first groundplan of the cave is by E. Ruffini from 1871. The first climatic observations were done by F. Fehér during 1870–1871. The cave was studied by J. A. Krenner as a commissioner of the Ugrian Natural Science Society in 1873. E. J. Pelech published a study on the cave in 1878, which was later issued in London.

The cave was visited by many famous personalities – prince August von Sachsen Gotha with escort, J. Petzval, K. Siegmeth, Serbian king Milan I., P. O. Hviezdoslav, S. H. Vajanský, M. Jókai, expedition of French artists with the builder of the Suez Canal F. Lessepse, Bulgarian tsar Ferdinand I., polar explorer F. Nansen and others. A concert for the tribute of Karl Ludwig von Habsburg was held in the Great Hall in 1890. The first summer skating took place in 1893.

The climatic research was done by the Ugrian Meteorological Institute headed by L. Steiner during 1911–1918. The Carpathian Club was doing the survey and observation in the between-war period, partially also the group for caving of the Section of VDT in Brno.

Non-glaciated parts were discovered in 1947 (Kvapľová sieň, Severná chodba and Biela sieň). A. Droppa studied the cave during 1950–1956. Turista, n. p., executed the general repair of the show path, electric lighting and performed protection measures during 1953–1954. The climatic measurements were renewed in 1950–1965 because of cave protection. They continued through 1976–1985, when also ice increments began to be observed.

The operation is performed by the Slovak Caves Administration since 1970. The cave was declared a protected natural creation in 1979. Since 1996, in connection with the act no. 287/1994 On Nature and Landscape Protection, it is enacted national nature monument. The cave is open to public as educational locality since 15th May to 30th September (4,5 month). 475 m is accessible for public, vertical distance is -43 m.

Since the Dobšinská Ice Cave is a genetic part of a large cave system in the Duča massif, the world heritage site includes also the Stratenská Cave and Psie diery Cave. These two speleologically connected caves make the second longest cave system in Slovakia, measuring 21,651 m. The Dobšinská Ice Cave measures 1,232 m. The ideas on its speleological connection with the Stratenská Cave were not realized from the conservation reasons, because of possible disturbing the speleoclimatic conditions.

The formation of the Stratenská cave system was shared except for the palaeoflow of Hnilec also by ponor waters of the Tiesňavy Brook. There are 5 developmental levels and two horizons determined in the cave. The most important is the IVth developmental level, which correlates with the main glaciated parts of the Dobšinská Ice Cave. The system of the Stratenská Cave is an outstanding illustration of underground karst development from the early Tertiary up to now in correlation with the geomorphological development of surface forms of relief of the adjacent part of the Slovak Paradise.

The Stratenská Cave stands out mainly by massiveness of domes and main passages. The Rozprávkový Dome with the volume of 79,017 m3 is the largest cave space in Slovakia. The flowstone fill is represented by stalagmites of mound, cone, pagoda, stick and other shapes. There are also straw stalactites, stalactites and flowstone curtains. Cave hemispheric pearls, aragonite crystalline protrusions, calcite eccentrics and gypsum are scarce. The Psie diery cave is a unique finding place of cave bear bones (Ursus spelaeus), which are 15,490 to 17, 530 years old.

Both caves are closed to the public. Their survey and research is done by volunteer cavers – members of the Slovak Speleological Society from the speleo club Slovak Paradise. The Stratenská Cave was discovered in 1972, vast underground spaces of the Psie diery Cave in 1988. Both caves were connected in 1994.

The preparation of the nomination project was a work of RNDr. L. Novotný and Ing. J. Tulis from the speleological club Slovenský raj, Slovak Caves Administration, as well as Slovak Paradise National Park.

The last technical improvements in the cave include a reconstruction of a part of the pathway in 1995–1997, reconstruction of electric lighting in 1999, a new entrance building was constructed during 1997–1998, an educational trail was set up along the access path to the cave in 1998. The interior of the entrance building has a permanent exhibition on caves of the Slovak Paradise, morphology and genesis of the Dobšinská Ice Cave and the system of the Stratenská Cave, speleoclimatic conditions, glaciation and history of the Dobšinská Ice Cave. The annual attendance is over 100,000 persons, which is connected with appropriate services.

The last research of the ice fill were done by the cavers from the speleological club Slovenský raj during 1995–1996, the detail geological research of the cave in 1998–1999. The chemistry of seepage waters was studied in 1998. Monitoring of chiropterofauna and climatic parameters is realized at present. Also the i geomorphological research of non-glaciated parts of the cave was started. The results of researches are necessary to apply and use in everyday operation of the cave especially concerning the creation and dynamics of ice fill.