Željnske jame (Caves of Željne) are extremely interesting, about 1600 m long horizontal cave system of the stream 'Rudniški potok' with several entrances. The stream flows below Kočevski Rog towards Podturn, where it appears in the stream Radeščica, the tributary of Krka.
The cave system is located shallow below the surface, as the ceilings are only 2-5 meters thick. A number of collisions have once divided the cave into three groups of tunnels. The system drains the water of nearby streams and drains it under the surface against Krka. Cave tunnels are predominantly erosive and are polluted only in individual places. The most beautiful is the Kapelica at Jama pri Koritu, which, however, is no longer accessible due to the deposited coal dust.
The most famous and easiest way to access is Ciganska jama (the Gypsy Cave), where a slender ceiling repeatedly hit the entrance part. There are several outstanding natural windows. It was named after the Roma (formerly called "Gypsies") who used the cave as a dwelling place or as a stable for horses.
The cave is an archaeological site from the Iron Age to the Palaeolithic. Nearly 20,000 years ago, an ice-age man arranged a hunting station in them. This is evidenced by numerous excavations during archaeological excavations at the entrance to the cave in the years 1963-1976. They found residues of charcoal, animal bones, and various stone tools: scrapers, clays, scrapers, bone scars.
Željnske jame cave system was sometimes transient and had the character of a branched tunnel from the Gypsy caves to the Cave at the trough. The passage through the channels through which the stream Rudniški potok runs today prevents the liquid mud from the deposited coal dust. The whole cave system is badly damaged today. The easy accessibility of the caves attracted numerous visitors who lit their torches and smoked calcium carbonate, crushed stonework, written on the walls, or found in the caves a repository for a wide variety of waste. Coal dust, flooded by the stream Rudniški potok into the caves, clogged the ditches and hit an already rich underground fauna. This is how the human fish disappeared, and now only the high waters flow from the underground.
Željnske caves are listed as the most important natural heritage of Slovenia and declared by the decree of the Municipality of Kočevje as a natural monument of local significance.