The Tiber is the third-longest river in Italy, rising in the Apennine Mountains in Emilia-Romagna and flowing 406 kilometres (252 mi) through Umbria and Lazio to the Tyrrhenian Sea.It drains a basin estimated at 17,375 square kilometres (6,709 sq mi). The river has achieved lasting fame as the main watercourse of the city of Rome, founded on its eastern banks.
In addition to numerous modern bridges over the Tiber in Rome, there remain several ancient bridges (now mostly pedestrian-only) that have survived in part (e.g., the Milvian Bridge and the Ponte Sant'Angelo) or in whole (Fabricius' Bridge).