Ancient Rome had much better defined and localized borders than the current ones. The town was organized inside its own walls: inside the Servian walls from the Republican Age to the first centuries of the Empire, and inside the larger Aurelian walls from the third century of the Christian period. Around them, the countryside, formed by the huge agricultural estates with villas in the middle of them or more modest country houses.
This clear division between the town and the surrounding countryside was preserved in the following periods until the unrestrained and speculative growth that involved the Roman countryside during almost all the 20th century.
Notes: The brochure is available in the Park Offices of Via Appia Antica, 42 and in the Info Points.