The literary tradition stating that there was some type of defensive wall or earthen works that encircled the city of Rome dating to the 6th century BC has been found to be false.

[8] Along part of the topographically weaker Northern perimeter was an agger, a defensive ramp of earth that was built up along the inside of the Servian Wall.

The Servian Wall became unnecessary as Rome became well protected by the ever-expanding strength of the field armies of the Republic and of the later Empire.

Expanding domestic structures simply incorporated existing wall sections into their foundations, an example of which survives in the Auditorium of Maecenas.

Another notable section on the Aventine Hill incorporates an arch that was supposedly for a defensive catapult from the late Republic.