The Chaos Wastes is a fictional place in Games Workshop's Warhammer Fantasy world setting. The Chaos Wastes are a vast warped, cold and barren wasteland to the north (and probably also the south) of the habitable areas of the world. It is referred to by the Norse as Shadowlands and sometimes as Umbra (or Umbra Chaotica). The Wastes are mentioned in many of the Warhammer sourcebooks. It borders Cathay, Naggaroth, Ogre Kingdoms and Norsca and the Eastern Steppes. Norsca and the Eastern Steppes are considered to be part of the Wastes.
The Chaos Wastes are inhabited by various mutated flora and fauna, Daemons, Chaos monsters (including Beastmen) and the barbaric human tribes of the Norse, Kurgan and Hung who worship Chaos gods whose influence is strong here. A great Chaos Portal between the material world and the Realm of Chaos spews raw magical energy, the stuff of Chaos, into the world. Several other, lesser rifts also exist in the wastes. Unstable energies change the climate, radically causing mutations to anybody moving there.
Champions of Chaos travel to the wastes to gain respect and rewards from their masters. The mightiest of these champions may even become a Daemon Prince. Followers of different Chaos gods constantly battle in the Wastes, until a powerful enough warlord unites the different tribes and starts a Chaos incursion to some location of the Warhammer World.
The mighty empire of Cathay has built a huge wall, known as 'The Great Bastion' (similar to the Great Wall of China) to protect their lands from invasion from the Chaos Wastes. The Dark Elves also maintain a series of watchtowers in order to prevent incursions into Naggaroth by the denizens of the Chaos Wastes.
Huge Chaos Monoliths are a common sight in the wastes.