G'Hanir

G'hanir is the Mother Tree, the biggest tree of Azeroth atop the biggest peak, which has the seeds of all tree species of Azeroth. The tree is a realm high in the sky above the clouds, where all the spirits of birds and winged creatures from all climates and zones of Azeroth are gathered after their death. Even the spirits of dragons inhabit G’hanir as the afterlife place. The demigoddess Aviana is the guardian of G'hanir.

G'hanir is apart from the real world, more akin to the Emerald Dream, but separate from both. Aviana died during the War of the Ancients, and her realm tree G'hanir died with her. Alexstrasza still held an acorn from G'hanir. When the War of the Ancients ended, Illidan had created a new Well of Eternity by releasing 3 vials of water from the original well into the lake at Mount Hyjal. Alexstrasza planted the acorn from G'hanir -- the Mother Tree, into the lake of Mount Hyjal, hoping to create a new World Tree, to replace the lost G'hanir. The New Tree was named Nordrassil.