The caves are situated in Central Bohemia, 7 km South of Beroun, in the middle of the nature reserve of Czech Karst, not far from the castles of Křivoklát and Karlštejn. The caves were discovered in 1950 and made accessible for the public in 1959. The caves originate in 400-million-year-old Devon calcite rocks, consist of three levels to be found 70 m under the ground-level, and over 2 km long. The accessible part is 620 m long and the sightseeing tour lasts 1 hour.The top level housed a 15th century secret workshop of money forgers. The caves can boast of unique opal-bearing decorations, as well as numerous paleonthological excavations, documenting the history of Earth Nature of the past 1.5 million years.