The Parkstein is famous for its impressive basalt outcrop. This basalt formation consists of pentagonal and hexagonal columns, up to one metre high, whose shafts extend into the earth to a depth of up to 30 metres. It is part of an old stream of lava that has been exposed at the surface after the softer rock above it had been weathered away over the course of millions of years. The wall of basalt measures 38 metres.