The Arno is a river in the Tuscany region of Italy. It is the most important river of central Italy after the Tiber.
The river originates on Mount Falterona in the Casentino area of the Apennines, and initially takes a southward curve. The river turns to the west near Arezzo passing through Florence, Empoli and Pisa, flowing into the Tyrrhenian Sea at Marina di Pisa.
With a length of 241 kilometres (150 mi), it is the largest river in the region.
