The houses that those walls were once scarcely wide enough to enclose have long since vanished, and their modern successors occupy but a third of the space once allotted to the capital of the Empire.
Beyond the walls immense suburbs stretched forth in the days of old.
Gorgeous villas, luxurious groves, temples, theatres, baths--interspersed by colonies of dwellings belonging to the lower orders of the people--surrounded the mighty city.

Of these innumerable abodes hardly a trace remains.

The modern traveller, as he looks forth over the site of the famous suburbs, beholds, here and there, a ruined aqueduct, or a crumbling tomb, tottering on the surface of a pestilential marsh.
The present entrance to Rome by the Porta del Popolo occupies the same site as the ancient Flaminian Gate.

Three great streets now lead from it towards the southern extremity of the city, and form with their tributaries the principal portion of modern Rome.

On one side they are bounded by the Pincian Hill, on the other by the Tiber.