Ostia Antica preserves the remains of the ancient city of Ostia, near the mouth of the Tiber southwest of central Rome. Its name is related to ostium, Latin for a river mouth, and the city’s early position beside the Tiber and coastal salt pans shaped its strategic role. A later flood changed the river’s course, while sediment and shoreline shifts left the archaeological area inland from today’s coast. The landscape is therefore part of the history, not simply a backdrop.
Roman literary tradition attributed Ostia’s foundation to King Ancus Marcius in the seventh century BCE. The archaeology tells a more cautious story: the earliest remains identified by the park belong to a fortified settlement, or castrum, of the fourth century BCE. That distinction matters. The foundation legend expresses how Romans remembered the city; excavated structures provide the firmest evidence for its early form. Ostia grew beyond the original fortifications, and a larger circuit of walls followed as the settlement expanded.
