The town of Castiglion d'Orcia is in the province of Siena and it is at 540 m of altitude. It has a population of about 2500 inhabitants. The church of Santa Maria Maddalena and the church of the Santi Stefano and Degna, as well as the suggestive square dedicated to the famous painter Lorenzo di Pietro called "il Vecchietta" can be admired in the town.

The town's origins date to the century after the year 1000, when the first built-up area figured in the long list of the Aldobrandeschi's feuds with the name of Petra. If the Abbey of San Salvatore ceded many towns to this powerful family, Petra had an opposite fate and it was handed to the monastery in 1154. At the beginning of the XIII century, Siena instituted its sovereignty in Castiglion d'Orcia with the Count Aldobrandino's assent.
In the XIV century, Castiglione finally went under the domination of Siena and it also became the seat of a vicariate. During the years, the Republic governed the territory by commissioning its administration from various families it was financially linked to. This was the case of the Piccolomini who were substituted by the Salimbeni in 1368. They transformed Castiglion d'Orcia into a real anti-Sienese stronghold and began a phase of harsh fights that culminated in 1418 with the establishment of the Republic and with the new conquest of the town.
At the half of the XVI century, Florence annexed Siena and its territories entered the Tuscan Grand Duchy. Thus, Castiglione was involved into the new process of feudalization of the Tuscan country as established by the Medici in the XVII century. In 1605, Cosimo II changed it into a marquisate and ceded it to the Riario, some nobles from Bologna. Castiglione had to wait for the abolition of feudalism, achieved by the "enlightened" ruler Pietro Leopoldo of Lorraine during the territorial reorganization carried out at the end of the XVIII century, to recover its dignity.