In Slavic mythology, Buyan (Буя́н) is described as a mysterious island in the ocean with an ability to appear and disappear. Three brothers – Northern, Western, and Eastern Winds – live there. A lot of strange things are said to happen on this island; Koschei the Deathless keeps his soul hidden there inside a needle placed inside an egg in the mystical oak-tree, while other legends call the island the source of all weather, created there and moved into the world by the god Perun.
Some scholars interpret Buyan as a sort of Proto-Indo-European Otherworld (see Fortunate Islands). Others assert that Buyan is actually a Slavic name for some real island, most likely Rügen.