Hyperborea is a fictional prehistoric continent devised by Clark Ashton Smith, distinct from the paradise of Greek mythology. In Smith's cycle it is a land of decaying civilizations, alien sorcery, and terrible gods such as Tsathoggua. The wizard Eibon is its most celebrated figure.
Smith's Hyperborean cycle was later integrated into the broader Cthulhu Mythos canon and now constitutes one of the primary prehistoric eras of the shared Lovecraftian universe.