Documented since the 12th century, but probably of more ancient origin, the Castrum of Borgo San Dalmazzo stood on the crest of the Monserrato hill allowing control of the three valleys that descend to the village: Gesso, Stura and Vermenagna valleys.
Several sources of the time mention the Castrum de Pedona as the site of different historical events, among which the meeting between the emperor, of the Holy Roman Empire, Federico Barbarossa and the Count of Barcelona Raimondo Berengario who died here (1162). Destroyed for the first time in 1231; rebuilt at the end of the same century, the castrum was conquered and destroyed several times over the centuries until the eighteenth century when the area of the Monserrato hill was put up for sale and purchased by the Grandis family.
The ruins rise in the upper part of the park and are today covered by vegetation and in a precarious state. Despite this situation, the base part of one of the sighting towers is clearly visible. In the lower part of the hill, the remains of the curtains alternate with supporting walls of the upper terraces. Halfway up, the ruins of a rectangular building of about 28×8 m rise, named by some sources of the 16th century as the “giesiassa”. Far away in a westerly direction there are some remains of a cylindrical tower about 10 m high and characterized by splayed lancet windows open towards the outside of the walls. At the top of the hill (altitude of 705m), there are the bases of a cylindrical tower of about 3 m in diameter, and a few metres away, an imposing wall of 5 m in length which could probably have been a shoulder of the castle. The construction system of these elements, composed of salvaged bricks alternated with river stones, allows us to date the structure to the fifteenth century.