Just near the Vittoriano is Trajan's Column, a monument to his victory over the Dacians, which after 19 centuries, was returned to its original majesty and splendor by careful restoration.
The above is an amalgam of two photos. It shows four maps mounted on a wall along the way to the Colosseum; the maps show the extent of the Roman Empire at various times. Click on the image for another page with the maps in a much better size. Alas I don't know what years the maps indicate.
The Colosseum, showing the full size of the intact wall. A large structure, even by today's standards.
Vittoriano