An inselberg or monadnock is an isolated rock hill, knob, ridge, or small mountain that rises abruptly from a gently sloping or virtually level surrounding plain.
In Southern Africa a similar formation of granite is known as a koppie, an Afrikaans word from the Dutch diminutive word kopje. If the inselberg is dome-shaped and formed from granite or gneiss, it can also be called a bornhardt, though not all bornhardts are inselbergs.
An inselberg results when a body of rock resistant to erosion, such as granite, occurring within a body of softer rocks, is exposed by differential erosion and lowering of the surrounding landscape.
Pietra di Bismantova in the Apennines, Italy
The Spitzkoppe of Namibia, a 670-metre (2,200 ft) granite peak formed by early Cretaceous rifting and magmatism.
Lion atop a koppie in the Serengeti, northern Tanzania
Mount Mulanje, a large inselberg in southeastern Malawi
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher than a hill, typically rising at least 300 metres (980 ft) above the surrounding land. A few mountains are isolated summits, but most occur in mountain ranges.
Mount Everest, Earth's highest mountain
Chimborazo, Ecuador, whose summit is the point farthest away from the Earth's center
Fuji volcano
Illustration of mountains that developed on a fold that has been thrust