The underworld or netherworld is an otherworld thought to be deep underground or beneath the surface of the world in most religions and mythologies. Typically it is a place where the souls of the departed go, an afterlife or a realm of the dead. Chthonic is the technical adjective for things of the underworld.
Underworlds by mythology
This list includes underworlds in various mythology, with links to corresponding articles.
This list includes rulers or guardians of the underworld in various mythologies, with links to corresponding articles.