From ancient Trebea to the rule of the Marquises of Monferrato. An intense history beginning just before the year one thousand, passing from the Feud of Cocconato, to the Radicati, to the Savoys. The pretty town centre was built on a hilltop around the castle. Next to it, built at the end of the 20th century, a small ricetto was formed, of which we can still find the ruins of a small tower and the entrance gate from the 16th century. Nearby we find the Church of St Mary Magdalene, once the castle chapel, enlarged over the centuries, and the Church of the Holy Trinity built in the 18th century in thanksgiving for the escape from war against the French army.
The church of San Siro is one of the oldest structures and dates back to medieval times; it is located on a hill near the Madonnina hamlet.
From Casalborgone you can access the Bosc Grand, an interesting route also due to the presence of the Ro Verda, a rare large tree defined by botanists as 'quercus crenata'.
A place of honour goes to the local pea, recognised as a traditional agri-food product by the Piedmont Region, to which a festival is dedicated every year in May. A day dedicated to agricultural work and the presentation of tasty dishes, including the 'Gogu', a tortellone stuffed with peas.