In Norse mythology, Alfheim is the realm of the elves. The elves were creatures of light, nothing like their counterparts, the dwarfs that live underground in Svartalfheim. The elves do not appear explicitly in the Norse Edda and its interpretations.
The Aesir gods grant Alfheim as a gift to Freyr when he cuts his first tooth, Basically, this makes him the King of the realm and its inhabitants. Talk about a generous tooth fairy!
After Christian influence, Alfheim has been considered to be one of the realms in Heaven.