Otherworld

In historical Indo-European religion, the concept of an otherworld, also known as an otherside, is reconstructed in comparative mythology. Its name is a calque of orbis alius (Latin for "other world/side"), a term used by Lucan in his description of the Celtic Otherworld.

Comparable religious, mythological or metaphysical concepts, such as a realm of supernatural beings and a realm of the dead, are found in cultures throughout the world. Spirits are thought to travel between worlds or layers of existence in such traditions, usually along an axis such as a giant tree, a tent pole, a river, a rope or mountains.