An inselberg or monadnock is a large rock formation that sits on its own, surrounded by flat lowlands. It can be a hill, ridge or small mountain. They are found in hot, dry areas of land. The name means "island mountain".
References
↑Neuendorf, Klaus K.E.; Mehl, Jr., James P.; Jackson, Julia A., eds. (2005). Glossary of Geology (5thed.). Alexandria, VA: American Geological Institute. ISBN0-922152-76-4.