Zone

A Zone is an alternate dimension separate from that of Mobius Prime with different properties and characteristics. Various zones can be reached via portal, technology or by using magic or magical items such as Chaos Emeralds. Some famous zones include the Twilight Zone and the Zone of Silence. Zones have been used as both places of banishment and confinement as well as safe havens, such as the various pocket zones Hawking created and sent both the Echidnas and Dingoes to in order to keep them safe from harmful radiation. (StH: #43, KtE: #3, #5, #18)

The term "zone" is also applied to various segments of Angel Island with dramatically different climates. (KMS: #1)

Known Alternate Universes/Zones (and planets)
Named
 * Dark Mobius
 * Discovery Zone
 * Light Mobius
 * Litigopolis
 * Luna Zone
 * Mobius Prime
 * Mobius-Seventeen
 * Moebius
 * No Zone
 * Planet Freedom
 * Sentai Zone
 * Sol Zone
 * Underground Universe

Unnamed
 * Alternate Mobius where Cyborg Sonic originates from
 * Future Mobius where NICOLE and Dr. Eggman originate from
 * Future Mobius with the Freedom Fighters of the Galaxy
 * Future Mobius where Silver the Hedgehog originates from
 * Alternate Mobius where Freedom Fighters are giant monsters
 * Alternate Mobius where Shade appeared
 * Alternate Mobius where Werehog appeared
 * Medieval universe
 * Prehistoric universe
 * Sonic X universe

Known Pocket Zones
Named
 * Collision Chaos Zone
 * Maginary World
 * Mirror Zone
 * Neutral Zone 1
 * Special Zone (formerly known as the Zone of Silence)
 * Void
 * Stardust Speedway Zone
 * Triple Trouble Zone
 * Twilight Zone (also called the Twilight Cage)
 * Virtual Zone

Unnamed
 * Horizont-Al and Verti-Cal's zone
 * Zone which Echidnaopolis was sent to by the Hyper-wave Projector
 * Zone which the Dingoes and their city was sent to by the Hyper-wave Projector
 * Pocket Zone where Super Sonic and Hyper Knuckles fought

Angel Island's Zones

 * Angel Zone
 * Forbidden Zone
 * Hidden Palace Zone
 * Ice Cap Zone
 * Lava Reef Zone
 * Marble Garden Zone
 * Mushroom Zone
 * Sandopolis Zone
 * Sky Sanctuary Zone

Background Information

 * In response to a fan query regarding whether or not the futures from which NICOLE and Dr. Eggman originated were the same, writer Ian Flynn stated that: That's up for debate, honestly. There's room to take it in both directions. For the sake of simplicity, I'd consider it the same. This way we're only dealing with three futures (Eggman/Nicole's, MxYL, Silver's) rather than four.
 * Writer Ian Flynn says that he is against reusing any characters or concepts that are blatant parodies of movies/TV shows/other media again, meaning that several characters and Zones are unlikely to appear again in the canon comic series.