The Formless Wastes, also known as the Chaotic Abyss and as the Land of Lost Souls, is a place situated within the otherworldy realm of the Warp.
It contains those areas of the Immaterium that do not fall under the dominion of one of the four Chaos Gods, with much of its landscape being random chaos that is forming and reforming based on the minds of mortals as well as the currents of the Realm of Chaos. Within the Formless Wastes sit rivers of tar that flow through petrified woodlands beneath crimson skies whilst great stairways go into the heavens where they connect to themselves in an endless loop that sit alongside castles of bone and fortresses of ichor amongst limbs with pillars of fire burning over the horizon. Every dream, nightmare and vision has a representation within the Formless Wastes which is also the home of the Daemonic Furies, where flocks of them watch for prey that falls within their sights.[1a]
Greater Daemons and Daemon Princes that are strong enough to demonstrate a level of control over their surroundings also make their homes within the Land of Lost Souls. These islands stand out within this chaotic wilderness with some only appearing for an instant whilst others are as old as the Great Powers. Each of these sub-realms is a small domain compared to that of the Chaos Gods though each embodies the whims of its creator and has a shrine or temple dedicated to its beliefs. Some are even populated by their own Daemons, though these are short-lived as they tend to be consumed by the Furies that populate the Formless Wastes.[1b] Within the Formless Wastes of the Immaterium resides the dark foundry known as the Forge of Souls.[1c]