alheimur
Alheimur is a fictional realm used in fantasy literature, games, and worldbuilding to denote a primordial or all-encompassing world that lies beyond ordinary reality. In many renditions, Alheimur functions as the source of magic, the seat of ancient powers, or a liminal space that connects different planes of existence. The term is typically presented with Nordic- or Norse-inspired flavor, though its exact origin is a modern coinage rather than a historic linguistic fact. It is commonly depicted as a multi-layered cosmos, sometimes described as a luminous outer realm, a central hub of reality, and an inaccessible inner core, with portals or rites required to traverse between Alheimur and mortal realms.
Variations across works reflect different mythologies and game systems. Some portray Alheimur as a living, sentient
In popular culture, Alheimur appears in indie fantasy novels and tabletop role-playing campaigns as a canonical
See also: astral plane, nine realms, world-tree, underworld.