The extensive Podpeč Cave is the best known of the underground caves situated under the Dobrepolje karst polje. The cave consists of a vast system of underground halls and passages providing home to an endemic salamander known as the olm. The map of the cave was first drawn up in 1687 by the famous Slovenian polymath Janez Vajkard Valvasor. His map was the first ever map of an underground cave in Slovenia and one of the earliest in Europe.
The distinctive appearance of the Podpeč Cave is due to the action of water, which flows in and out of the cave. The water accumulating in the cave occasionally floods the cave's near surroundings. Visitors are only admitted to the cave's large entrance hall, which passes into two narrow passages formed by the action of water.
Access to the cave's other halls and several subterranean lakes is only possible for those equipped with caving and scuba-diving gear and guided by speleologists. The most attractive part of the cave is the magnificent Crystal Hall, where only speleologists can go.
In the vicinity of the Podpeč Cave there several other interesting karst caves, the best known being the 130-metre-long and 10-metre-deep Kompolje Cave, the Tekavča jama cave, the cave next to the Church of St. Anthony above the village of Zdenska vas, the Tatarica cave, and the Špelkna jama cave in the village of Podtabor.