This indicator shows the occurrence of individual types of valuable natural features and the protection regime for entering karst caves.

Valuable natural features include all natural heritage sites on the territory of the Republic of Slovenia. A valuable natural feature is defined as a rare, valuable or well-known natural phenomenon as well as any other valuable phenomenon that is part of living or non-living nature, a natural area or part of a natural area, an ecosystem, landscape or designed landscape. This includes geological phenomena, minerals and fossils and their sites, surface and subterranean karst phenomena, subterranean caves, gorges and narrows as well as other geomorphological phenomena, glaciers and glacial forms, springs, rapids, waterfalls, lakes, bogs, brooks and rivers with banks, the seashore, plant and animal species, their exceptional specimens and habitats, ecosystems, landscape and designed landscape.

Valuable natural features of national importance comprise features that are of international or great national importance and which are under the jurisdiction of the state. Others are of local importance and are protected by the local communities. All valuable natural features within protected areas established by the state are of national importance. Features of national importance also include all subterranean caves, which have been given the status of geomorphologically valuable natural features.

Pursuant to a regulation governing subterranean caves, every cave has been placed under one of three protection regimes as regards access. Accordingly, caves are divided into closed caves, where the natural cave environment is vulnerable to such a degree that it could be damaged or threatened by any entry of humans into the cave, open caves with supervised access, where the natural environment is vulnerable to such a degree that it could be damaged or threatened by any unsupervised entry of humans, and open caves that can be visited without limitations and cannot be damaged as long as the general protection regime is observed.