"Buyan" by Ivan Bilibin
In Slavic mythology, Buyan (Буя́н sometimes transliterated as Bujan) is described as a mysterious island in the ocean with the ability to appear and disappear using tides. Three brothers—Northern, Western, and Eastern Winds—live there.
It figures prominently in many famous myths; Koschei the Deathless keeps his soul hidden there, secreted inside a needle placed inside an egg in the mystical oak-tree; other legends call the island the source of all weather, created there and sent forth into the world by the god Perun. It is also mentioned in The Tale of Tsar Saltan, of His Son the Renowned and Mighty Bogatyr Prince Gvidon Saltanovich, and of the Beautiful Princess-Swan (an opera by Nikolai Rimsky-Korsakov) and many other Slavic folktales.
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.