Special Zone
From Sonic Retro
In the Fleetway's Sonic the Comic, the Special Zone is a kind of alternate reality where special stages take place. It has strange physics compared to Mobius.
It is also the home of the Chaotix crew, and Lord Sidewinder is often found there.
Recently, it was supposedly destroyed by Shadow in the semi-offical web continuation in an attempt to gain the power of the Chaos Emeralds, though it may yet return.