The building renewal tied to the presence of the Emperor Maximianus and his court in the city modified its layout considerably. In fact, the construction of the Imperial residence and the Circus definitely determined the vacating of several central city areas and consequently, the expansion of residential areas well beyond the Late-Republican walls to the East, which were then surrounded by walls in their turn; the new perimeter of the walls became 4,500 meters long. In the West, the walls partially surrounded the recently constructed Circus which had loopholes in its curved side for defensive purposes. Imposing evidence of its urban undertaking can be seen in the garden of the Civiche Raccolte Archeologiche (Civic Archeological Collection) in the form of a twenty-four sided tower linked to a large section of a wall, the foundations of which continue down into the basement of the museum.
