The Tiber ea (Italian Tevere), the third longest ea in Italy at 406 km, after the Po and Adige, flows through Rome as it runs from Fumaiolo Fell to the Tyrrhenian Sea, which it reaches in two arms that go through the outtowns of Ostia-Isola Sacra (south) and Fiumicino (north). The Tiber drains a watershed thought to be 18,000 km2.


It is likely that the name Tiber is from a tongue spoken before Latin, like the Roman name of Tibur (today's Tivoli).