Iacon is the capital city of Cybertron's northern hub in almost every Transformers continuity. Before the Great War, Iacon was the seat of Cybertronian government and the crowning jewel of Transformer society. As the Decepticons' campaign of terror spread across Cybertron, the Autobots and their sympathizers withdrew from their respective city-states and fled toward Iacon, the last bastion of freedom left on the planet. However, as the centuries passed and the conflict escalated, Iacon's defenses were worn down and the great hub city fell as well. With the fall of Iacon, Cybertron's core systems started failing and prompted the Autobots to consider a planetwide evacuation to seek out new energy sources to sustain themselves.
Prior to the Beast Wars era, Cybertron went through a period of re-development known as the Great Upgrade and Iacon was abandoned. The city of Cybertropolis was built over Iacon's remnants, but many of the old city's systems remain functional and various landmarks have been left relatively untouched.