It is the seat of The Town Council.
It was the seat of the Registry of the Municipality. Renewed in 1992, this recatangular plan building is now the public library “G. Colombo” (it preserves about 20000 books ) and the municipal historical archive (over 4000 archival pre-unification units). In this building there were the archives of the town, of the jurisdiction, the clerk of the court’s house and a big hall for the meetings of the General Council of the community.
These complete Palazzo di Monte which is located right in front of them. Although originally they were attribuited to Sangallo and just later to Sansovino, nowadays we can say that Nanni di Baccio Bigio was the artist who built them (explicitly Vasari mentioned a lodge open on three sides, Corso Sangallo, Via delle Logge and Via Sansovino, speaking about the works he realized in Monte San Savino). They include another two connected buildings: the open gallery and a three storey building.
Today this pyramidal stone obelisk looks very worn out. On the top there is a sphere supporting the Florentine lily. The community of Monte San Savino erected it in 1644 because in the May of that year Mattias de Medici, Granduke Ferdinando II’s brother, was invested with the fief of Monte San Savino.
Il Cassero is the ancient fortress of Ajalta. Nowadays, from the square, we can see only its facade. It is a three story building with a rectangular perimeter, built on a square base, with sloped walls, a sturdy dungeon and four angular watch towers (some parts of these structures can be seen only from inside the Cassero). The merlon has been partially rebuilt.
Its most ancient parts were restored in 1729-32 and more recently, in 1800.In 1799 the Jewish community who had settled in Monte San Savino in 1627 was banished and the building became property of the Jewish University of Siena. Later, some private citizens bought it, but since 1924 it has been the property of the town of Monte San Savino (that had provided for its most urgent repairs).