Tiber

Tiber, a river of Italy celebrated in ancient Roman history, rises in the Apennines, in the province of Arezzo, Tuscany; rapid and turbid in its upper course, but navigable 100 m. upwards from its mouth; flows generally in a S. direction, and after a course of about 260 m. enters the Mediterranean about 15 m. below Rome.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)