Castell'Azzara is a town in the province of Grosseto, set on the southern slopes of the Mount Amiata, at about 820 meters asl. According to the legend, in 1212 three Albobrandini brothers (Ildebrandino, Bonifacio and Guglielmo), admiring their possessions from the Mount Penna, the beauty of this land and its strategic position, decided to built there a castle and drew lots who of them would have had to built it (the place name, in fact, derives from "zara", meaning "dice"). Owned by the Aldobrandeschi counts, the town passed to the Santa Fiora branch and, later, to powerful families from Orvieto and Siena; in 1439 it was acquired by marriage by the Sforza, in 1600 it was sold to the Medici and, finally, it was annexed to the Grand Duchy of Tuscan.
For many centuries the town economy was based on mining activity.
- the Aldobrandeschi stronghold, built by the Aldobrandeschi family in the XIII century, is located in the historical town center of Castell'Azzara. It consists of a main building on three levels and a clock tower;
- the Sforza Villa, built by the cardinal Alessandro Sforza along the ancient Via Francigena. Although it was one of the favorite residences of the Sforza family, after a century of its construction the decline of the ville began. Acquired by the town council in 1980, after a long and careful restoration, this beautiful Renaissance residence went back to the glories of the past.
- the remains of the Rocca Silvana, an Aldobrandeschi's stronghold;
- the Church of San Nicola, set in front of the Aldobrandeschi stronghold, has Medieval origins with three naves;
- the Church of San Gregorio Magno, near the Sforza Villa;
- the XVI century Church of Madonna del Rosario, with valuable frescoes;
- the XVIII century Church of San Nicola da Tolentino, in the mining village of Selvena;
- the Sassocolato Grotto;
- the cinnabar mine site, whose mining activity ended in 1970s, was known since the Etruscan period.