The Metropolis Zone was a huge, industrial city made entirely of pipes, mechanical contraptions, and huge factories controlled by Dr. Eggman during the period when Dr. Eggman's Operation: Clean Sweep altered reality and reshaped Mobius.
During the period when Dr. Eggman's Operation: Clean Sweep altered reality and reshaped Mobius, Sonic and Tails, after splitting from Sally Acorn, Boomer, and Antoine, infiltrated the base in their search for Dr. Eggman. After a brief battle with his newest machine, Eggman retreated to the newly launched Death Egg. (StH: #228, #229)
- The Metropolis Zone was a level from the game Sonic the Hedgehog 2.