During the past centuries both the architectural structure and the ecclesiastic organization that ruled it have had many changes. In the beginning it was ruled by four priests called “San Guglielmo pensioners” as they were under the authority of a monastery ruled by “Guglielmiti” monks that was situated near Acerona. The church was probably dedicated to San Leonardo because this saint was worshipped in the monastery near Acerona. In 1618 the church was elevated to the status of “distinguished collegiate church” ruled by a Chapter composed of seven priests; the Archpriest was the major authority of the chapter. The community that had rights of possession of San Leonardo used to make the nomination of the Archpriest and of the other six priests. Besides Canonries, including also the Deposition of Jesus Christ, there were also five Benefits, owned by some eminent families from San Casciano that elected on their own the priests charged of them. The 17th and 18th centuries were the periods of major magnificence for the church that was visited very often by Bishops and Cardinals from Italy and from abroad, coming to San Casciano’s spa for treatments. The church has had many changes also in its architectural structure. In the beginning the church was supposed to be settled on a west/east axis instead of the today’s south/north direction. The entrance was on the side that is now occupied by the Oratory of Sant’Antonio, as it was shown when the present portal was found on that side. The style was surely gothic with a lot of elements made of worked travertine, as we can see from the portal and from the remains of cornices and columns. The present direction was probably given in the 16th century, when the Company of Sant’Antonio was founded and the respective church was built. The bell tower was built in 1606.

that was founded between the end of the 15th century and the beginning of the 16th century had its seat in the church dedicated to Sant’Antonio, which is next to San Leonardo. The Company also possessed two Hospitals: one of them was in the village and the other one was next to “Santa Maria della Colonna alle Terme” church, each hospital was ruled by a representative elected by the Council of the Company. Also Sant’Antonio has had many architectural changes, especially in the 18th century. In 1741 the steps connecting the church to San Leonardo that had been placed at first on one side of the high altar dedicated to San Cassiano were moved. In 1748 many works modified the internal aspect of the church that was given a baroque look thanks to the building of a circular apse and of artificial travertine columns. Ten years later the master Pietro Sperone finished the stuccoes that decorated the apse. A wooden statue representing the Virgin with the Infant Jesus is also inside the church.

Company of Sant’Antonio had its seat in this church. It was ruled by a Council of Brothers that elected a Chief Prior, a Second Prior and the Third Priors that had the effective task to run the Company; they were in charge for three years. The Company also ruled a third Hospital located in “Pozzo”. This is the only church among the three of them that lie inside the town walls that still keeps its original structure. Some frescoes made by Pomarancio are inside the church. Inside the church is also buried “Beato Pietro”, a hermit that died of cold, following the tradition, on the steps of the church.

and was one of the early Christian parishes that composed the diocese of Chiusi, but it has always been said that it was built on the ruins of a pagan temple. During many centuries, at least until the end of the 11th century, the church, called “Santa Maria ad balneo”, maintained its role as parish, being a point of reference for urban settlements, as it is testified on documents of the period. The extremely peripheral position in relation to the present village is the result of the urban and demographic reductions that happened in San Casciano during the centuries. After the loss of the status of parish Santa Maria has done spiritual assistance for people coming for thermal treatments. Very soon spiritual assistance was completed with material assistance, thanks to the creation of a new Hospital for the poorest people coming for treatments. Many frescoes from the schools of Orvieto and Siena are inside the church.

is one of the most suggestive monuments in the area. The only nave is enriched with two side chapels. One of them is dedicated to the Virgin and is elegantly decorated in the “Dome of Siena” style, with the typical black and white colours. The circular apse was built on one of the circular towers of the defensive system.

the façade is higher than the roof and its soaring and well-proportioned frontal gives movement. The church has three entrances. Above the central door there was a window made of terracotta from 1937 reproducing the Virgin that was removed to enlarge the door itself. A rose window, also made of terracotta, elegantly gives the finishing touches to the façade. The church is baroque inside, with three naves. The plan of the church is quadrangular, with two side chapels placed along the naves, at their halves; the altars of these chapels are dedicated to “Madonna of Rosary” and to “St. Antony of Padua”. Next to the left door there is a baptistry made of travertine from San Casciano.

and it was also the Podestà’s residence. The building of the adjoining castle modified its original structure. The façade and the entrance-hall are decorated with the coats of arms belonging to some of San Casciano’s podestàs. On the façade left side there is one column where the old units of measurement of San Casciano are reproduced. An architrave from the 16th century with the coat of arms of the Commune is also conserved in the entrance-hall. An Etruscan funerary urn made of terracotta is conserved in the Mayor’s office.

happened in two different moments: the first time the eastern part was concerned (including the present “rione del Campanile” and “rione della Porticciola”); the second time the western part was concerned (including Gattineto and Pozzo). This theory is based on scripts of the “1559 Lira” where the existence of two town districts is reported: the Castle and the Village, corresponding to the above-mentioned parts. Some ruins of the ancient walls are presently conserved in the eastern part of the town centre, other parts of walls are incorporated in other buildings, walls on the north-western side have probably disappeared because of landslides or because of damages caused by the production of saltpetre (potassium nitrate) as Gherardini and Pecci have testified. Another cause of demolition of the walls was the need of stones to build or to repair houses. The walls on the eastern side included the door “Caldagna”, that was pulled down at the beginning of the 20th century. North of that door, walls above the street level are missing, but they still keep their function of support, the only part one can see is only the connection between the former door and a tower that has partly been rebuilt. South of the door Caldagna walls are prevailingly elevated in comparison with the street level and are connected to the pentagonal tower. Access to San Casciano was possible through three doors: the “Porta”, which was the main entrance and was located south on the present Matteotti Square, the “Porticciola” north, and Caldagna east, that does not exist any more.

The town centre still has a particular quadrangular structure with large and very straight streets and a big square, which is disproportionate to the present size of the village.

the Republic of Siena commissioned to Biagio De Stinis the extension of the castle so that it could have a quadrangular plan. Four towers bound the castle at the summits: the old tower (the quadrangular one, that was adapted to the new military requirements thanks to the building of the buttress and to the restoration of merlons and brackets), the main tower, the half round tower and the tower called “saracinesca” (portcullis). The latter is not mentioned on documents from that period, but it appears on subsequent documents and likely had the function to protect the entrance of the castle. A relief in the soil was also lowered on the western side, as it was the only real danger for an artillery attack. The attack of the papal army in 1451 interrupted the works, even if they were already finished as for the essential structures. In 1466 the Republic of Siena sent the master Giovanni Gori from San Quirico to finish the works in Fighine.