Aggtelek & Baradla

The Caves of Aggtelek Karst and Slovak Karst are over 1,000 karst caves spread across 55,800 hectares along the border between Hungary and Slovakia. They were inscribed as a UNESCO World Heritage Site in 1995, for an exceptional diversity of karst structures and for cave systems that developed under both temperate and tropical processes, which is a rare combination to find in one place.

The listing has seven components, three in Hungary and four in Slovakia. The Hungarian ones are Aggtelek, Szendrő-Rudabánya Hill and Esztramos. The Slovak ones are Dobšiná Ice Cave, the Koniar plateau, the Plešivec plateau, and a component beside Silica and Jasov.

Of the thousand-odd caves, several stand out: the Baradla and Domica complex, Gombasek Cave, Silica Ice Cave, Dobšiná Ice Cave, the Ochtinská Aragonite Cave and Jasovská Cave.

Baradla-Domica is the headline. It runs 21 km, with roughly a quarter on the Slovak side and the rest in Hungary, so the cave crosses an international border underground.

The two halves have different histories. Baradla is first mentioned in writing in 1549 and has been a tourist attraction since 1920. Domica, the Slovak part, was not found until 1926, by Ján Majko, and its tourist circuit opened afterwards.

That gap of nearly four hundred years between the first written mention of one end and the discovery of the other says something about how these systems are learned: from both ends, slowly, and long after people first went in.

The cave has been surveyed in stages over two centuries. Joseph Sartory made the first survey in 1794; by 1825 only 1.8 km was known, and that year the engineer Imre Vass pushed a further 5 km along the main branch and produced an accurate map. The system is now known to run more than 25.5 km, and there are traces of Neolithic occupation at its natural entrances. Domica was lived in as far back as 5000 BC and is an important archaeological site of the Bükk Culture.

One neighbour deserves its own mention. Dobšiná Ice Cave was found in 1870 by Eugen Ruffinyi, opened to the public a year later, and in 1887 became the first electrically lit cave in Europe. The ice on its floor approaches 25 metres thick.