From Wikipedia: Jötunheimr (or Jǫtunheimr; often anglicized as Jotunheim) is the homeland of the Jötnar, the giants in Norse mythology.
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, the protection wall to the 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.
Jotunheimen (Norwegian pronunciation: [ˈjuːtʉnˌhæɪmən], the home of the Jotnar) is a mountainous area of roughly 3,500 km² in southern Norway and is part of the long range known as the Scandinavian Mountains. The 29 highest mountains in Norway are all in Jotunheimen, including the very highest – Galdhøpiggen (2469 m). Jotunheimen straddles the border between the counties of Oppland and Sogn og Fjordane.