Hyperborea

Hyperborea is the "land beyond the North-wind" in Greek mythology. The country is an island located far in the north beyond the "lands of the Celts", but nevertheless graced with a temperate climate which allows a sophisticated civilization to flourish. The people of Hyperborea live in peace, freedom and prosperity and worship Apollo, to whom they have dedicated a large round temple.

Hyperborea has been sought in many locations, some of them unlikely (e.g., a sunken island at the North Pole), some more plausible (e.g., the British Isles; maybe the British Elves). It may even have been the same place as Atlantis.