Cybertropolis

Cybertropolis was the capital city of Cybertron in the time after the Pax Cybertronia, built atop the old Autobot city of Iacon. The city became Megatron's base of operations after his takeover of Cybertron. At one point, Megatron had the city reconfigured so that he could move the buildings, which he used to briefly trap the Maximals- the final purpose of this was unknown.