Yggdrasil

In most Nordic beliefs, it is known that the world is but a small spherical fruit hanging from the tree of Yggdrasil, the World Tree. It is said that the Æsir, Allfather, created the tree at the cost of his own life-force.

Nine Realms
There are said to be nine realms of Yggdrasil including our own, Midgard or Imlorian, the land of earth and water. The others are Jötunheim, the land of ice and giants; Muspelheim, the land of magma and flame; Alfheim, the land of light and serenity; Svartalfheim, the land of darkness and chaos; Vanaheim, the land of magic and wonder; Helheim, the land of perdition and suffering; Niflheim, the land of mist and purgatory; and finally Asgard, the land of valour and glory.

Disambiguation
In Vikken belief, it is said the Yggdrasil is a physical tree which had sprouted forth from the void of Ginungigap and that the Gods had nurtured it and the nine realms had been born from their will.

In Druidry, it is found that Yggdrasil is not physically a tree but more so a road which can be traversed astrally by those skilled enough to tap into it. Seiðr of similar understanding but still view it organically as Vikkens do.