The Valdarno is the valley of the river Arno, although it does not apply to the entire basin of the river. The usage of the term generally excludes Casentino and the valleys formed by the major tributaries, such as the Val di Chiana, the Val d'Ambra, The valley of the Sieve, namely Mugello, the Valdelsa, and the Valdera. The areas surrounding the towns of Arezzo, Florence and Pisa is also excluded.
The most important towns are:
Coordinates: 43°34′N 11°32′E / 43.567°N 11.533°E / 43.567; 11.533