The largest caves in the northeastern part of Bohemia. The caves are open to public for guided tours. The tours are not physically challenging and are offered to families with children.

The caves in the territory of the Prachovské Skály are pseudo-karst. They were formed in the rocks and rock towers of rectangular sandstone.

The rock wall of the Klokočské Skály comprises numerous large and small caverns. The best-known one was named Postojna.