Yggdrasil, the World Tree, is a colossal tree, the base of which supports the Vashnar Mountains and the very Pillars of Heaven. It is said to stretch through not only much of Sapience, but a good majority of the planar multiverse as well. Nestled in its branches is the draconic planar nexus known as the Parthren Gare, while the lowest tips of its roots pierce the infernal plane of the Underworld. By way of Yggdrasil, the Gods and any They permit may travel with ease to any plane in existence. The best view of the tree is said to be in the Garden of the Gods itself, where one can see it stretching high into the sky in all its glory.
In the year 758 AF, The Vigil trying to conjure the powers of the elements unwilling released Pazuzu, the demon prince. In a desperate attempt to flee he went to the Flame of Yggdrasil and cleaved it open allow adventurers to enter the planar multiverse and visit the different planes and worlds held within its branches by travelling up them.
The most famous feature of the World Tree is the Flame of Yggdrasil.
The fabled shard of Yggdrasian flame, a rare artefact sold at auction in 541 AF, is an encapsulated fragment of the World Tree's resurrective potency which returns adventurers to life from any location.