Cave halls (exceeding 50 meters in height)

Beneath the valley of Rakov Škocjan lies a network of caves through which the Rak stream travels, and the largest of these underground spaces are halls on the scale of a cathedral nave. The valley sits between Cerknica and Postojna, at the foot of the Javorniki hills, and the cave halls explain its shape: where the roof of a very large cave collapsed, a green canyon was left, and where parts of the roof survived, they now form natural bridges. The halls under and around the valley, reported to rise more than fifty metres, are among the most impressive in the Classical Karst, and they are one of the reasons geologists have studied the area for generations.

The water that shaped them comes from far away. The Rak is fed by the underground outflow from the area around Lake Cerknica, which fills and empties with the seasons, and it reaches the valley through the Zelške Caves, where it emerges into daylight. After a short run in the open, it disappears again, flows through further caves, and continues toward Planina Cave, where it joins other streams. Eventually this water forms part of the Ljubljanica river system, which is sometimes called the river of seven names because it changes its name as it crosses the karst. Understanding this connection is part of the pleasure of visiting, because the stream and the caves are parts of one system.

Inside, the formations are those typical of limestone caves: stalactites hanging from the roof, stalagmites rising from the floor, flowstone coating the walls and, in the lower levels, pools and channels where the river still runs. The scale is what stands out, with chambers so wide and high that lamps barely reach the roof. Most of the larger cave system is a protected area, and entry to many parts is limited to trained cavers or to visits arranged with the park authorities, so the casual visitor should check what is available before planning a trip. The entrances to the caves and the viewpoints above them can be reached without special equipment.

The nearby Educational trail passes the main points of interest, and it explains the caves, the natural bridges and the vegetation. The Little Natural Bridge (Mali Naravni Most) and the Natural bridges are further highlights, with a View of the Big Natural Bridge (Veliki Naravni Most) from the north. The Karst formations and the Underground river passages can be appreciated from the surface by following the stream. This area suits visitors with an interest in geology, and it is quiet and calm.