The Otherworld is a hellish alternate dimension of the town of Silent Hill. The Otherworld is one of three "layers", or worlds, of which the town depicts itself. The first is just a regular version and the second, the "Fog World", is a seemingly abandoned town populated by monsters and some characters with an unnatural fog present. The third, the Otherworld, is a hellish, nightmare world created by the main character's psyche and sometimes other supporting characters' psyche. Usually a shift occurs in which the player is transported from the Fog World to the Otherworld with little warning. During a shift, an air raid siren can often be heard in the distance. Members of the religious cult, The Order, call this realm their "holy land" and could have an influence in the shifts. Members are given a certain degree of protection in this world. Originally, the Otherworld was only limited to the town itself but has expanded into other neighboring cities like Shepard's Glen and Ashfield (specifically South Ashfield).
This realm has many defining features that separates itself from the real world and the Fog World. The shift to this realm usually happens inside structures, like Brookhaven Hospital, but can happen outdoors, too. The world is populated with a greater number of monsters and some can even respawn. The world is depicted as being rusted and ruined. Most of it composed out of rusty brown metal floors, and bloodstained walls. Some walls are even made entirely out of flesh. Grating, fencing, and barb wire is also a common sight. Elements such as industrial fans, chains, hooks, and corpses are also very common. When outside, roads are usually turned into metal fenced floors with nothing beneath but darkness. Instead of fog, a pitch blackness covers the area, both inside and out.