The town of Castelnuovo used to belong half to the Riva lords and half to the Biandrate counts, before passing to the Monferrato marquises at the behest of the emperor. Later subjected to the authority of Asti, it was made a feud in 1288 until, after returning to the Monferrato marquises, it was enfeoffed in 1546 by Anna d'Alençon and Giovanni Enrico Suave. After coming into the possession of the Savoys it was granted in 1619 by Charles Emmanuel I to Count Ernesto di Mansfelt and on his death it passed to his sister Matilde di Savoia, wife of Carlo di Simina, whose family maintained the seigniory until the 18th century.
The town was the birthplace of Don Bosco, and was named after him in the 19th century.
At the highest point in the centre of the town rises the square medieval tower, rebuilt in the 15th century. Together with the adjacent ruins, it is all that remains today of the medieval castle.
After visiting the tower and the castle ruins in the upper part of Castelnuovo, take in the beautiful panorama from the open area in front of the castle before walking down towards the lower part of the town, to the Palazzo dei Rivalba. Inside the chapel of the same name.
Giovanni Melchiorre Bosco (John Bosco) founded the congregations of the Salesians and the Daughters of Mary Help of Christians and was canonized by Pope Pius XI in 1934.
Sant'Andrea church with an 18th-century façade and a painting by Guglielmo Caccia called il Moncalvo; Art Nouveau-style Casa Filipello and garden; next to the tower, the late-18th-century baroque Madonna del Castello sanctuary.
Along the road that leads to Berzano di San Pietro is the Romanesque church of Sant'Eusebio with medieval characteristics: a Lombard band along the apsidal part. The Romanesque church of Santa Maria di Rasetto in Garesio has an intact exterior. In Bardella, around 2 km away, is a cold sulphurous spring used said to be good for the digestive system and the skin.
Malvasia and Freisa DOC wines; rush and wicker crafts
Convivio medieval dinner (3 June); La Ronda di Mercanti historical re-enactment with food and wine celebration (12 June); fair (13 June); truffle fair (mid-November)