Drevenik – National Nature Reserve was declared one of the oldest protected areas in Slovakia in 1933. Drevenik is our most extensive travertine territory with karstic morphology. It was created by connection of travertine mounds settled from mineral springs. Its contemporary form resembles Table Mountain inclined slightly north-east. There can be found grikes and swallow hole. Rock towns emerged on the rift broken extremity - graceful Kamenný Raj (The Rock Paradise) in the eastern part and a bizarre naturalistically most valuable steep Peklo (The Hell) in the western part of the area. South-west part is full of caves with archaeological discoveries of primeval man. Twenty-four caves have been described so far. Summer temperature reaches only 0-1 °C.
It is suitable for ecotourism, hiking, climbing, riding and speleological tourism.