Rome is an inland city; no sea borders it directly. The nearest coastline is the Tyrrhenian Sea (part of the Mediterranean), approximately 25 km (15.5 miles) west of the city center at Ostia Lido—Rome's historic port and modern beach district.
Ancient Rome's port was Ostia (later supplemented by Portus). The Tiber River connected the city to the sea. Modern Rome expanded to absorb Ostia as a municipality (Roma X Municipio), but the historic center remains inland.