(from German Insel, “island,” and Berg, “mountain”), isolated hill that stands above well-developed plains and appears not unlike an island rising from the sea. The early German explorers of southern Africa were impressed by such features, and they dubbed the domed or castlelike highlands inselbergs. Spectacular examples include Ayers Rock and the Olga Rocks in central Australia.

Inselbergs are relict features. They have maintained their relief as the adjacent surrounding landscape was lowered. C.R. Twidale of Australia demonstrated the role of subsurface weathering in shaping the flanking hillslopes and pediments of granitic inselbergs.

The occurrence of inselbergs implies immense variations in the rates of degradational activity on the land surface. These structures are one of several varieties of landform called paleoforms that can survive with little modification for tens of millions of years. In inselberg landscapes, the active erosional processes are confined to valley sides and valley floors.