When the Mountain Amiata was not yet territory of Siena, people called our Montagnola territory “Mountain” and to distinct the two locations with the same name, one was called Radi di montagna and the other Radi di Creta (near Monteroni d’Arbia). From the ancient fortification, which was in a magnificent panoramic position, today there still are a stone tower with doors and arched windows, some houses and a Romanesque church. The church, dedicated to S. Maria and recorded since 1276, is built in cavernous limestone and presents, to the right of the facade, a bell tower. Radi has probably a Lombard etymology. Recently a spear and a Lombard sword have been discovered in a nearby farm, we can assume that a settlement of this folk gave origin to the castle. Although it is located in the diocese of Volterra, in 1189 a third part of it belonged to the bishop of Siena, as reported in a document of Pope Clement III. In the thirteenth century, after having joined the State of Siena, the castle became the seat of a small hamlet. At the end of the century it was briefly occupied by the powerful Aldobrandeschi family of Santa Fiora but was regained by Siena in 1300. In 1312 it was attacked and conquered by Ranieri del Porrina who, taking advantage of the turmoil brought by the army of Emperor Henry VII, was trying to create a small, elegant State in the territories around Casole d'Elsa. Only after the Emperor's death, the 24th of August 1313, Siena was able to regain Casole and Radi, while Ranieri escaped to Pisa, where he remained in exile for several years.
The castle is actually closed.