A border area between the territories of Siena and Florence, Castellina in Chianti was the scene of clashes throughout the Middle Ages. The Republic of Florence ordered the construction of this fortress at the beginning of 1400, following the powerful attack of the Milanese duke Gian Galeazzo Visconti, ally of Siena. Together with the fortress was also strengthened the walls connected to it, which took the shape of an irregular hexagon. The fortress proved to be strong in 1452, when it resisted a siege by the Sienese that lasted 44 days. It remained the property of Florence until the 1920s, when it was purchased by the Municipality and restored according to its presumed original appearance. Until the last years of the last century it was the seat of the municipal offices, which is why it overlooks what is called "Piazza del Comune" ("Town Hall Square"), the heart of the town. Since 2006 it houses the Archaeological Museum of Chianti Senese, which contains all the archaeological findings of the territory. In addition to visiting the rooms of the medieval fortress, you can go up to the top of the tower, from which you can enjoy a breathtaking view.