Otherworld is an enchanted land in another dimension, which somehow occupies the same space — but on a different level of reality — as Great Britain does throughout the multiverse, and provides a link between all the various permutations of Britain in different universes. It is the current location of Camelot, the home of King Arthur. Otherworld also contains the Starlight Citadel, home of the Omniversal Guardian Roma, and the temple of the Green Knight, patron of the Knights of Pendragon. It is also the base of operations of the Captain Britain Corps.
Notable residents of Otherworld include the aforementioned Roma; her father Merlyn; Vortigen, Herne and the other Proud Walkers; a race of Elves which included Moondog and Jackdaw; and (formerly) Captain Britain. Otherworld appears to be connected in some way to the Netherworld ruled by Mandrac the Nether God, and has long been under threat of invasion by the demonic Necromon and his servant Mordred. Others who have visited it include the heroic X-Men and Excalibur. A portal to Otherworld has been shown to exist on Darkmoor.