The World Tree

The tale of the World Tree dates back to the times before The Scouring, before the nations of Elibe. Some versions of the tale put it at a time before the Chained Oblivion was sealed away, a time when the gods still walked the land. Regardless of the time, or the people who tell the tale, many common threads bind together the history of the World Tree.
When the gods created mortals, they wanted their creations to interact with everything there was to interact with, across the tumultuous planar boundaries. As these fledgling races had little to no understanding of the magic that was woven into the world, the gods had to create pathways for them. These pathways were anchored in the roots of a massive tree grown by the Wildmother, Melora. Those who traveled to this tree could walk through the portals to other worlds: worlds of elemental chaos brought to order by the gods, worlds that mirrored the material plane, and emergent pocket worlds created for the gods to rest in.
This tree was visible for miles, as it extended into the clouds. Its branches spanned across the sky, casting the area beneath its canopy in near-constant darkness, keeping most people from staying nearby, only coming to travel between the planes.
Over the centuries, the magic that created the World Tree faded, portals ceasing to exist, the leaves and branches of the tree withering, leaving nothing behind. Since the gods no longer walk the face of Elibe, no force has been powerful enough to create a new World Tree, and the planes remain difficult to travel across, as the magic required to pass through the planar barriers is unattainable to most practitioners.
As most cultures have a version of the World Tree myth, the supposed location of this tree is unknown to the world at large.