Tiber

River in Italy that flows through Rome; its length from its source in the Apennines to the Tyrrhenian Sea is 400 km/250 mi. It is Italy's third longest river.

The Tiber rises on the eastern borders of Tuscany, and flows generally south past Perugia and Rome to the sea near Lido di Roma. It is joined near Narni by the Nera, its most important tributary; other tributaries are the Aniene, the Chiani, and the Paglia. The Tiber empties into the sea via two channels: the silted-up Fiumara to the south; and the canalized Fiumicino. On the latter branch, close to Rome's international airport, is a hexagonal port built by Trajan. The land mass between the channels was once known as the Sacred Island, or the Isle of Venus. Small ships can sail up river as far as Rome.