Arno

Arno (ancient Arnus), river, central Italy, in Tuscany. From the source of the river on Mount Falterona in the Apennines, the Arno flows generally south before turning north-west at Arezzo, then through the cities of Florence and Pisa, to the Ligurian Sea. Navigation by barges is possible as far as Florence, but it requires caution against the sudden floods that sometimes swell the stream. Flood control measures have been in place for centuries, including some designed by Leonardo da Vinci, but nevertheless a disastrous flood of 1966 did an enormous amount of damage to artworks in Florence.