This splendid structure is situated on colle di San Donato, where stood the ancient buildings dating back to the II-III century BC and three hundred.
The fortress was built between 1538 and 1560 under the will of Cosimo I de 'Medici.
The building was partly destroyed by the French nell'Ottocento and further renovated in several occasions starting in 1868.
Its trapezoidal-shaped structure, designed by Antonio da Sangallo and Nanni Hungary is a perfect witness to the sixteenth century military architecture built above the area of medieval citadel, which are well see two bulwarks of the East side and some of curtain.
Fortress was formerly with three gates and surrounded by a wide moat on the west side are still visible injuries caused by a powerful explosion of a device.
The Tourists can enjoy a splendid panoramic view of the city and the plains of Arezzo and Val D'Arno.
Inside the visitor can admire an intricate network of rooms, tunnels and wells, located in various points Fortezza's.