Norse cosmology, as it is given us in the source material for Norse mythology recognizes the existence of nine worlds, assigned the ending -heimr (home, realm, or world) or in some cases -garðr (homestead, yard or earth). Apart from Miðgarðr (the "Middle Earth," or the world as we know it), the remaining eight worlds can be structured into pairs of opposing principles:

The worlds are all connected by Yggdrasil, the world tree. However, there is some inconsistency in the sources, as the world tree – drawing its nutrition from three wells, located in three different worlds – suggests that they are all roughly on the same level, which would indicate for instance a Niflheim in the north, a Muspelheim in the south and a Jotunheim in the east.

On the other hand, the Prose Edda locates Asgard and Alfheim in "the heavens,". The underworld Hel is generally said to border or be situated in Niflheim, yielding a more layered cosmology, something like the chart below. (Rasmus B. Anderson's 1897 translation of the Younger Edda gives a slightly different layering, however.)

The theory and diagram presented here only represent one possible interpretation.

• Yggdrasil (Beneath its roots are the nine worlds of the universe, plus three magic wells)
  • Hvergelmir
  • Mímisbrunnr
  • Urdarbrunnr
• Highest level
  • Álfheim (The world of the elves)
  • Asgard (The world of the Æsir, originally called Godheim)
    • Valhalla
  • Vanaheim (The world of the Vanir)
• Middle level
  • Jotunheim (the world of the Jotnir, i.e. giants)
    • Gastropnir
    • Thrymheim
    • Utgard
  • Midgard (The "Middle Earth," the world of men, originally called Mannheim)
  • Niðavellir and Svartálfheim (The world of the dwarves or Dark elves. Most probably the same)
• Lower level
  • Ginnungagap (Former gap between Muspelheim and Niflheim, from which life sprang)
  • Hel (The world of Hel, goddess of the underworld)
    • Náströnd
  • Muspelheim (The world of fire and home to the fire giants)
  • Niflheim (The world of mists, ice and cold. Home to the frost giants before they were killed by the flood of the blood of Ymir)

Norse mythology | Indo-European mythology | Mythological Cosmologies

Cosmologia escandinava | Severská kosmologie | Nordisk kosmologi | Σκανδιναβική κοσμολογία | Cosmología Nórdica | Cosmologia della mitologia norrena | היקום במיתולוגיה הנורדית | Skandinavų kosmologija | Noordse kosmologie | 九つの世界 | Norrøn kosmologi | Nordijska kozmologija