Le livre des terres imaginées, Guillaume Duprat, éd. Seuil Jeunesse, 2006, pp.37 et 39.
Ydddrasil, the viking tree, that ties together the lands of the gods, giants, elves, humans and the dead.
The center of the Earth coïncides with the center of the world,where stands a wonderful tree named “Yggdrasil”. It is a giant tree, a sort of highway between the lands of the gods, giants, elves, humans and the dead. In northern myths, men live on the “Middle Earth”, a circular land, surrounded by a mountain chain. Around it lies a sea where Jörmundgand lives, a giant snake that bites its own tail.