The valley of the Arno River is formed by the most important river in Tuscany, which, as it flows from the Casentino along its course, characterizes two areas: the upper Valdarno, including the provinces of Arezzo and Florence to the Gonfolina narrows, and the lower Valdarno which stretches from Montelupo to Pisa, where the river then flows into the sea.

It is a wide valley enclosed between the Pratomagno Apennines and the higher hills of the Chianti, where the river passes through the "Valley of Hell" - a long ravine where there are now two reservoirs - to then leave through the "Incisa Narrows". The hilly and mountainous areas are the most appealing. In the hills you can admire the natural rock formations shaped like pyramids and blades, known as "the cliffs", as well as the prestigious olive-tree groves and the extensive vineyards that produce the famous DOCG Chianti wines. In the higher areas you encounter dense chestnut and beech-tree forests, while on the Pratomagno, vegetation gives way to vast grassy meadows.

Throughout the area artifacts have been found that testify to the presence of human settlements in the Stone Age, Etruscan and then Roman times, when the "Cassia Vetus" and "Cassia Adrianea" roads were built. The churches of the Valdarno, which are of great historical and artistic beauty (such as the Pieve di San Vito a Loppiano), were built along these ancient roads. During the Medieval times the first castles were built for military use because the land was disputed between Arezzo, Florence and Siena. After the victory of Florence in the battle of Campaldino, the valley was under the control of the Florentine Republic. The main towns of the Upper Valdarno are Montevarchi, San Giovanni Valdarno, Levane, Figline Val d'Arno, Terranuova Bracciolini, Incisa Val d'Arno (where you can admire the Franciscan complex SS. Cosma and Damiano al Vivaio, which was built as a hospice for pilgrims), as well as Castelfranco di Sopra, Pian di Scò, Reggello and Rignano sull'Arno, which offer a scenery of castles, valleys and churches of great beauty and charm.

The traditional cuisine in the area is characterized by 'poor food' . "Lampredotto", which you can also find in street-vendor kiosks, is a tripe that took its name from "lamprey", a kind of primordial edible eel. Whereas, "Finocchiona" is a cured meat made from minced pork and seasoned with red wine and wild fennel seeds. Moreover, the "prosciutto di Pratomagno" (seasoned ham) is much sought after because it is particularly flavorful and seasoned, and in fact, has received the D.O.P. quality label. Also the "zolfino bean", which only grows in this area, is very popular for its thin skin and mealy flesh.

The "Stufato alla Sangiovannese" (stew) is a special dish typical of San Giovanni Valdarno, which recently received the label of uniqueness and authenticity. This is a dish made of animal offal and  the meat of the front legs of adult veal and then seasoned with a secret blend of spices.

The Lower Valdarno begins at Montelupo Fiorentino, a castle that was built by the Florentines to counter Capraia, situated on the other side of the Arno river.

Here the river flows into the landscape which becomes flat and uniform, yet certainly more interesting from a historical and artistic point of view because along its course it encounters towns and villages of medieval origins, but nowadays for the most part, active industrial and commercial centers: Empoli (with its large Collegiata), Fuccechio, Castelfranco di Sotto (where nearby you will find the Santa Maria a Monte castle), Santa Croce sull'Arno, Montopoli, San Miniato (full of works of art), Pontedera, Cascina and lastly Pisa, which with its leaning tower greets the traveler and the Arno river, which after just a few kilometers flows into the Tyrrhenian Sea.