Metropolis City

Metropolis, also called Metropolis City or the City of Metropolis, is the largest city on Sonic's World, located on West Side Island by the Blue Ridge mountains.

Name
In pre-modern times it was named Mobotropolis after the Kingdom of Mobius of which it was the capital. During and after the Great War it took the name Robotropolis while under Dr. Ivo "Eggman" Robotnik's control, and the neutral name Metropolis emerged after the city gained independence following the fall of the Eggman Empire.

Metropolis also gives its name to New Metropolis, built by the Eggman Empire prior to the War to Take Back the Planet.