Fort San Giovanni which was built around a pre-existing tower between 1640 and 1644 to a design by the Spanish commander Ferdinando Glazer. The perimeter of the fort is developed adapting itself to the hillside and is characterized, in the south, by high pincer walls with hanging guards on the edges.
The territory of Finale, already belonging to the Del Carretto marquisate, in 1598 was sold to the Spanish Crown, interested in having access to the sea through which to reach, without passing through the port of Genoa, the Duchy of Milan and Flanders.
With this objective projects were started for the adaptation of the fortifications, the construction of a new port and the improvement of the road between Finale and Milan.The complex was modernized and extended throughout the 1600s; on the occasion of the passage of the infamous Margaret of Spain in 1666, the engineer Gaspare Beretta carried out the work of setting up the road along which the fort is located and which took its name, destined to unite the Finale to the territories of Monferrato and Milan .
When in 1713 Finale passed to the Republic of Genoa, the fort was partially demolished in the northern part. Since then it was abandoned until 1822, when the Savoy government adapted it to prison, a destination that it maintained until the early 1900s.