The Tiber (Latin Tiberis, Italian Tevere) is the thir-longest river in Italy, rising in the Apennine mountains of Tuscany and flowing 406 kilometres through Umbria and Lazio to the Tyrrhenian Sea. It drains a basin estimated at 18,000 km². The river has achieved lasting fame as the main watercourse of the city of Rome, founded on its eastern banks.