The Chýnov cave was discovered in 1863 during works in a quarry. In 1868, after necessary adaptations, this became the first Czech cave accessible to the public. The original stone staircases can still be seen there and the tour around the cave is a small trip to the history. The Chýnov cave was formed in stages by corrosion, which widened various fissures, aided by water running through the fissures and washing out solid substances. The principal wealth of the cave is not stalactites and stalagmites but colourful walls and ceilings, where white, yellow and brown marble facets take turns with dark amphibolite fillings. These two materials are the source of the remarkable circular shapes to be seen in the walls. The steep corridors of the cave go as deep as 41 m down to the surface level of an underground stream. The total length of the cave system, not fully investigated yet, is over 1,200 m, with 220 m already accessible to the visitors. The spaces outside the sightseeing tour are under speleologists’ and speleo-divers’ investigation, which in the 1980’s and 90’s resulted in the discovery of extensive, permanently water-filled spaces with unique druses of flint stone and other minerals.