Forbidden Zone

The Forbidden Zone is the name given to two separate locations. One is a region on Angel Island, the other is a desolate region located on Mobius' surface.

Angel Island's Forbidden Zone
The Forbidden Zone on Angel Island is known for being largely uninhabited. It is also the location of Haven, the base of operations for the Brotherhood of Guardians. It was also briefly home to Black Death and Enchantress, two wielders of dark magic. (StH: #45, KtE: #19)

Surface-Based Forbidden Zone
The Forbidden Zone on the surface of Mobius is primarily made up of dry, rocky wastelands and desert. Located in the outer reaches of Mobotropolis, the Knothole Freedom Fighters ventured into the Forbidden Zone with the recently discovered Nicole on a mission given by the late Julayla. After getting past a number of monstrous creatures and obstacles, such as the Cyclops Robot, the Griffon and the Polysaurus Rex. Sally discovered a treasure chest with a piece of paper saying"To thine own self be true" inscribed on it, which was presumably left by a version of herself from Nicole's home reality. (IYF)

One of Dr. Ivo Robotnik's factories was located in the Forbidden Zone. The Destructix took control of the factory in 3236 and attempted to sell it to Doctor Eggman. In 3237, Sonic the Hedgehog went to the derelict town of Gravestone in the Forbidden Zone when he received word that Tommy Turtle could be found there. He ended up rescuing a fake version of Tommy after fighting a group of Robot-duplicates of the Destructix. (StH: #117, #135)