Yggdrasil, the World Tree of Norse mythology, was a giant ash which held Asgard, Alfheim and Vanaheim in it’s branches, Hel, Niflheim, and Muspelheim in it’s roots, and pierced the centre of Midgardr as the world’s axis. The Word Tree has more than one guise, features in many Norse legends, and is the tree on which Odin hung for nine nights without food or water, his side pierced by his own spear (Gungnir), in order to learn the runes and gain wisdom.
I hung on that windy tree for nine nights wounded by my own spear,
I hung to that tree, and no one knows where it is rooted.
None gave me food. None gave me drink. Into the abyss I stared
until I spied the runes. I seized them up, and, howling, fell
It’s even suggested that the Norse may have hung ritual sacrifices of men, women, children, and even animals…always in ahs trees. A sacrifice to the gods.