There stands an ash named Yggdrasil,
A tall tree showered with white hail.
From there come the dews that drop in the valleys.
It stands forever green above the Well of Destiny.
Yggdrasil is the "world tree" in Norse mythology. In the mythology, the nine worlds (including Midgard, the human world) sit in the branches of the tree.
The three norn, Urd, Verdandi and Skuld, sit at the base of the tree, above the Well of Destiny, weaving the fates of men.