Located in Iacon, the Great Dome is the city-state's center piece. It outlines Iacon Central and provides protection to the Celestial Spires, where the government of Iacon is seated. Currently the Great Dome functions as the main Autobot base on Cybertron. Because Iacon tends to be the place that the Autobots protect best, the Dome and the Spires are of symbolic importance to them and they often refer to them to signify amazement, surprise or exasperation.