The town's name derives from the presence of an ancient castle, which was probably destroyed by Spanish troops in the XVII century. It is a town in the province of Cuneo, whose territories are composed not only from the town center, but also by a number of villages situated on the border with the province of Asti. The area was inhabited by populations of Gallo-Celtic since the II century B.C. and unexpectedly reacted harshly to the attempted invasion by the Romans, led by Appius Claudius, who was interested in opening an access road to reach the Gallia. After the fall of the Roman Empire the territories were left without a government o ruler and were occupied by the Barbarians till 950 A.D. During the later centuries the town submitted the domain of the Aleramo, founder of Monferrato, and their successors. In the early XVIII century the territory was ruled by the Savoy family that ceded Castiglione in fief to the Verasis-Asinari. With Napoleon, the town was annexed to France.
- the Shrine of Our Lady of Good Counsel in the village of Balbi. A votive shrine with a picture of the Virgin, that was brought here from Rome, on display here since the XV century. In 1817, after the occurrence of a miraculous event and the consequent increase of the faithful visiting, the shrine was rebuilt and a few years later, in 1838, around it was erected a small church. The current building was completed in 1857 and renovated in the XX century and is surmounted by a pediment and flanked by a Bell Tower;
- the Parish Church of St. Andrew is a Baroque style building erected in the XX century on the site where once stood the ancient castle. Inside the choir, the altar, the sacristy and other items belonged to the old church of St Andrew, dating from year 1000, damaged several times over the centuries and now desecrated;
- the Church of San Giorgio, built for the first time in 1843 and refurbished in 1730 and 1984;
- the Church of San Martino, dedicated to Our Lady del Carmine, which was built in 1750 and restored in the mid XIX century;
- the XVII century Church of San Bovo, rebuilt in 1867;
- the Church of San Carlo, originally just a shrine, built and blessed in 1758 and later enlarged;
- the Church of St. Peter Martyr in the village Balbi restored in 1751.