The castle of Montarrenti is built on a spur of rock at a height of 345 meters. The lords of Montarrenti were mentioned for the first time in a document of 1107 and they were bound, during the twelfth and thirteenth centuries, to the powerful Aldobrandeschi and Gherardeschi families. In this period the community of Montarrenti increased its own population and in the early years of the thirteenth century it became a little town. We know that in 1217 the lords of the castle and the consuls of Montarrenti together, swore loyalty to Siena. In 1318 the village of Montarrenti consisted of a fortress with a keep, two buildings, about thirty houses and a church dedicated to S. Lucia. During the fourteenth century the economic decline of the settlement and its gradual depopulation began. Of all the buildings that formed it, today there are only two towers and a small building, that have been restored in the last decades of the last century. The archaeological excavations that were carried out between 1982 and 1987 made it possible to reconstruct the earliest stages of the settlement, leading to the identification of a first fortified village dating half of the VII century.