Old Megaopolis was used by Dr. Eggman as a hideout when he constructed a new robotic body for himself after his old one was destroyed. Almost a year later Old Megaopolis' harbour was used by Eggman, where he planned to launch two nuclear missiles at Knothole and Station Square from his battleship. Before the missiles could launch however his battleship was taken out by Bunnie Rabbot. (StH: #116, #130, #133) New Megaopolis was constructed slightly north of Old Megaopolis, just outside its ruins, and towered over the older city's remains. (StH: #137)