We'll do together a walk through the Roman ruins in this old town. Its history, rich and fascinating, is witnessed today by the countless monuments that are worth visiting because in excellent condition. The first settlement can be traced back to the beginning of the 4th century B.C. Only at the end of that century a squared fortified encampent (castrum) was built. This military camp, called Ostia from the Latin word Ostium meaning "mouth of the river", was established at a distance of around 16 miles from Rome, as a military outpost to keep under control not only the access to the Tiber and the nearby areas, in order to defend Rome.

The city was then surrounded by a new circle of walls that is traditionally attributed at the time of Sulla. The walls circumscribed an urban area of about 50 hectares which could be accessed through three main gates: Porta Romana,Porta Laurentina and Porta Marina.