Jötunheimr (or Jǫtunheimr; often anglicized Jotunheim) is one of the Nine Worlds and the homeland (heim 'home') of the Giants of Norse Mythology — Rock Giants and Frost Giants.
From Jötunheimr, the giants menace the humans in Midgard and the gods in Asgard. The river Ifing (Old Norse, Ífingr) separates Asgard, the realm of the gods, from Jötunheimr, the land of giants. Gastropnir, home of Menglad, and Þrymheimr, home of Þjazi, were both located in Jötunheimr, which was ruled by King Thrym. Glæsisvellir was a location in Jötunheimr, where lived the giant Gudmund, father of Höfund. Utgard was a stronghold surrounding the land of the giants.