The Tiber (, Latin Tiberis, Italian , ) is the third-longest river in Italy, rising in the Apennine Mountains in Emilia-Romagna and flowing through Umbria and Lazio, where it is joined by the Aniene river, to the Tyrrhenian Sea. It drains a basin estimated at . The river has achieved lasting fame as the main watercourse of the city of Rome, founded on its eastern banks.