Spiral Yssgaroth

The Yssgaroth's Universe is an alternate dimension featured in The Pit. The Yssgaroth's Universe is mostly desert, though this may be just an illusion. The universe has unusual proportions and distances, which makes travel more difficult. There are many settlements of suffering humans, who are generally used as slave labour.

Many species have been accidentally brought to the universe, including Humans, Ogrons, Terileptils, the Galk and Bapputchin. Other species (such as the Cun) were either native or just unknown to the Doctor. Still other species (such as the Hunters) could naturally travel to the Yssgaroth's Universe.

The Time Lords originally discovered the universe when they were doing early test making black holes. Instead of making a black hole, they accidentally released the Yssgaroths. Other opening to the Yssgaroth's Universe can be found in 1800s London, near Stonehenge and on the unnamed planet in the Althosian system.