The Truth is a section of the Otherworld in Silent Hill: Requiem.
The Truth is a much less dangerous and dark version of the normal Otherworld, however it represents a place for revelation, and reveals to the person there their deepest guilt, fear, and/or pain, after which it triggers a shift to the true Otherworld, with differences depending on the person's character, and reveals the manifestation of that emotion. It can be interpreted as a place that gives someone a chance at redemption. It appears as a large circular room with a well in the center. It has a more ancient temple look than industrial like the rest of the Otherworld, and it has a light blue hue. Monsters are nonexistent in this room until one looks into the well at the center and realized their Truth, afterwards a manifestation of their darkest emotion appears.
The Truth is a location of a person's own Otherworld, and therefore is a place deep in the back of their minds where their darkest repressed emotions lie. If a person can look deep enough inside themselves, by venturing deep enough into the Otherworld, and travelling through The Void they will eventually come across this room.