A tumulus (plural tumuli) is a mound of earth and stones raised over a grave or graves. Tumuli are also known as barrows, burial mounds or kurgans, and may be found throughout much of the world. A cairn, which is a mound of stones built for various purposes, may also originally have been a tumulus. The method of inhumation may involve a dolmen, a cist, a mortuary enclosure, a mortuary house, or a chamber tomb. Examples of barrows include Duggleby Howe and Maeshowe.