Monteriggioni is a commune in the Province of Siena in the Italian region Tuscany. It borders on the communes of Casole d'Elsa, Castellina in Chianti, Castelnuovo Berardenga, Colle di Val d'Elsa, Poggibonsi, Siena and Sovicille.
Sitting on a small natural hillock, this completely walled medieval town in the Siena Province of Tuscany was built in the 13th century by the overlords of Siena to command the Cassia Road running through the Val d'Elsa and Val Staggia just to the west of Monteriggioni. Today, the town of Monteriggioni is the principal center in the modern Comune of Monteriggioni which encompasses 19.49 square kilometers in the area around the town. Distances from other major towns and cities are: Siena 15 km; Volterra - 39 km; Florence 50 km; Pisa 157 km; Lucca - 123 km; Arezzo - 121 km; Rome - 250 km
Except for some work done in the 16th century, very little work has been done to Monteriggioni's walls or buildings since they were first erected. So, Monteriggioni's walls and the buildings that make up the town within are the best preserved example of their kind in all of Italy, so it is not surprising that it attracts busses full of tourists, but also architects, and medieval historians and archaeologists.
The town served as a defensive fortification that played a vital role in the on-going conflicts between Siena and Florence during the Middle Ages when Florence was driving hard to increase its territory. Over the years, Monteriggioni successfully withstood many attacks from the Fiorentini and a few from forces under the command of the Bishop of Volterra which also asserted dominion over the area).
What Florence could not do by force, it ultimately achieved by guile. The Sienese had placed control of the town's garrison in the hands of Giovannino Zeti, who had been exiled from Florence. Reconciling with the Medicis in 1554, in what is known in Monteriggioni as the "great betrayal", he simply handed the keys of the town over to the Medicean forces.
The more or less circular walls with a total length of about 570 meters were built between 1213 and 1219, following the natural contours of the hill. There are fourteen towers on square bases set at equidistance, and two portals or gates. One gate, the Porta Fiorentina opens toward Florence to the north, and the other, the Porta Romana, faces Rome to the south. The main street within the walls connects the two gates in a more or less straight line.
The main piazza, the Piazza Roma, is dominated by a Romanesque church with a simple, plain facade. Other houses, some in the Renaissance style, once owned by local nobles, gentry and wealthy merchants facing into the piazza. Off the main piazza smaller streets give way to public gardens fronted by the other houses and small businesses of the town. Back in more hostile times, these gardens provided vital sustenance when enemies gathered without.