The door into Outer Kael is in the Walk of Glory in Eastern Wastes, at -251, -280, 4484 . The contested dungeon, Kael Drakkel, can be accessed through here.
Although this is technically an outdoor zone, flying is not permitted.
There are no enemies in Outer Kael, only a couple of quest givers for the Kael Drakkel quest series. The architecture is designed for giants, so small races will have difficulties moving in here.