Chýnovská jeskyně National Nature Monument

The Chýnovská jeskyně Cave NNM was declared in 1949 and covers an area of 1ha (the lands with the entrance to the cave). The monument lies on the southern slopes of the Pacova hora Hill (589m) close to the village of Dolní Hořice and 2km north-east of the town of Chýnov in the Jihočeský kraj - South Bohemian Region. The cave was discovered in 1863 during quarrying work and after some alterations in 1868 it became the first cave on the territory of the Czech Republic to be opened to the public.
The subject of the protection is the most extensive cave system in the south Bohemian Region, which developed in the coarse-grained crystalline limestone and in non-karst rocks. The cave is a notable geological and mineralogical locality and a natural hibernating site for several bat species (the largest known hibernating site for the Natterer’s bat in Europe).
The tectonically disturbed Hořice strata, which is built of metamorphosed rocks of varied series of the Moldanubicum runs in an east-west direction and is tilted to the north at an angle of 45-55°. These strata are between 50 and 100 metres in thickness and are built of crystalline limestone which was deposited in fine-grained dolomitic limestone to dolomite, above and below which there are strata of green-black amphibolites which include smaller bodies of calc-silicate rock, quartzites and cherts. The whole Hořice strata is bedded in mica-schist gneisses and mica-schists.
The caves are found in a body of relatively pure crystalline limestone (marble) up to 12 metres in thickness, which developed in the upper section of the Carboniferous strata. The main reason why the cave was formed was the corrosion of the Carboniferous rocks which took place especially around tectonic faults. For this reason the majority of the passageways are in the form of fissures or tunnels.
The cave system includes more than 1.5km of researched and documented tunnels which formed at several drainage levels – the lowest levels are permanently flooded. On the basis of hydrogeological and geophysical research we can predict that the cave system is much more extensive than the areas which have already been discovered. A total of 260 metres of passages have been adapted and opened to the public.
We find very few dripstone decorations in the Chýnov Cave, but on the other hand the cave can demonstrate the complex modelling of the cave spaces and the unique colouring of the water-washed walls, which is especially due to the alternating dark-green amphibolites and bleached areas of crystalline limestone and dolomite, as well as the presence of other chemical elements. The cave is also unique for its rich representation of mineral forms. The most significant of these is the discovery of purple variety of tremolite (called hexagonite). The Chýnovská jeskyně Cave is one of only two localities in the world where this mineral has been found.
Of the nine species of bat which have been recorded here, the most numerous are Daubenton’s bat (Myotis daubentonii), brown long-eared bat (Plecotus auritis), Natterer’s bat (Myotis nattereri), and greater mouse-eared bat (Myotis myotis). Occasional sightings have also been made of whiskered bat (Myotis mystacinus), Brandt’s bat (Myotis brandtii), barbastelle (Barbastella barbastellus) and the serotine (Eptesicus serotinus).
The cave is open to the public during the summer season. Most of the significant cave features can be seen during your guided tour. The cave is closed during the winter months, so that the hibernating bats are not disturbed.
Opening hours:
April, May, June, September, October: 9.00 – 15.30
July, August: 9.00 – 16.30