Central City in Sonic Chronicles is a sprawling human conurbation, home to G.U.N. Headquarters and Tails' workshop, along with construction sites, shops, and houses. Sonic and Amy arrive here from Green Hill Zone in the north, to meet up with Tails. The city is being terrorized both by giant wasp swarms on the rooftops and obsolete Eggman robots in the streets, both of which Sonic can dispatch in due course.
Robotnik apparently had a number of secret laboratories right under G.U.N.'s nose in the metropolitan area, as the team have to search the sewers and back alleys for any sign of recent activity in the fat man's supposedly "abandoned" hideouts.
Central City is where Tails and Rouge can be recruited to join Sonic's party. Tails' workshop in the north-east also serves as the team's base of operations between Chapters 2 and 4.
The music used here is a remix of the music used in Diamond Dust Zone in the Genesis version of Sonic 3D: Flickies' Island.