The Castello Monforte, ancient defence structure that was already in existence by 1300 and later modified various times, rises from the upper part of Campobasso. It bears the name of Count Nicola di Monforte who rebuilt the castle after an earthquake in 1456. The count was also responsible for the addition of an artificial moat and a drawbridge, of which few traces remain, and for the four cylindrical towers at the corners.
The structure is a solid, tall fortification on a quadrangular layout, with small windows similar to arrow slits, Guelph merlons and a rectangular tower with the function of a keep, whose summit offers a wide view over the neighbouring area. The simple interior is bare, with a large empty space followed by an inner room which was previously used as a memorial for the war dead, while the tower is today the headquarters of the Air Force Campobasso weather station.
