Mugello extends along the upper course of the Sieve river, which initially flows from northwest to southeast, then changes direction to northeast southwest. This valley, rich in history and culture, is bordered to the north by the Apennine watershed, marked by important mountain passes such as the Passo della Futa, the Passo del Giogo di Scarperia, the Passo della Colla di Casaglia and the Passo del Muraglione. To the south, however, Mugello is separated from the Arno valley and Florence by the ridges of Monte Giovi, Vetta le Croci, Monte Senario and le Croci di Calenzano, known as a whole as Monti Mugellani.
Today Mugello is identified with the portion of the Sieve river basin upstream of the confluence with the San Godenzo ditch, also known as the Comano stream, near Dicomano. This area corresponds to the ancient lake of marine origin, whose damming is still discernible from the conformation of the landscape: the hills on both sides of the river seem to close with each other, about three kilometers before Dicomano, near the railway bridge that crosses the Sieve. From this point to the confluence with the Arno in Pontassieve, the river flows in the so-called Val di Sieve.
The territory of Mugello is divided into two main geographical areas: Mugello proper and Alto Mugello or Tuscan Romagna. The Mugello valley includes the wide basin bordered to the north by the Apennines, where the historic villages of San Piero a Sieve, Barberino di Mugello, Scarperia, Borgo San Lorenzo, Vicchio and Dicomano rise. Continuing east, there is the municipality of San Godenzo, bordering the National Park of the Casentinesi Forests. Alto Mugello, located beyond the Apennine ridge, includes the municipalities of Firenzuola, Palazzuolo sul Senio and Marradi. These areas, although administratively belonging to Tuscany, have strong historical and cultural ties with Romagna. The landscape is extremely varied: from the gentle hilly reliefs, shaped by agriculture, to the massive Apennine ridges characterized by cliffs and geological formations of great interest. Here there are lush forests of beech, chestnut and oak, vast areas of pastures and areas of Mediterranean scrub. In the milder valley bottoms, on the other hand, the classic Tuscan crops develop, with olive trees, vines and cypresses, often within farms that adopt organic practices. From a morphological point of view, Mugello represents an intermontane basin, derived from the ancient Pliocene lake of about 300 square kilometers that occupied the region at the end of the Tertiary. This depression, now drained by the Sieve river, is bordered