Oblivion
Oblivion is the name given to the island added in the Throne of Oblivion expantion which contains two new macrozones called "Plain of Ashes" and "Bone Marches". The zones consistently only host mobiles of the undead variety, including animated skeletons, gouhls, and Vampires.
Access
To reach Oblivion, one must enter the black "Death Gate" which is located on every runegate in the world.