Monte Porzio is located on the ridge of a small hill relief bordering the northern side of the lower Cesano valley .
Though many archaeologically interesting pieces dating back to the Stone Age or to the Roman Period were found in the area, the town was founded by the Gauls. It was mentioned in the oldest documentary sources with the name of castrum montis podii. It is the Montevecchio family, starting from 1400, that gave the town its architectonic structure, building the Montevecchio Palace and the whole historic centre.
It belonged at the beginning to the abbey of San Lorenzo in Campo and in 1428 was given to the lieutenant of Carlo Malatesta, Count “Guido di Mirabello”;  high up on the village there's the small square with the old Municipal Palace (nowdays seat of the library) with a lovely clock tower.
Castelvecchio, part of the municipality, owes its name to the old Fortress (or Castle), which has been restored and transformed many times (once an ancient "Rocca Roveresca") : a fortress with a moat, corbels and  polygonal towers with four vertices. Deserves also to be visited: the parish church of St. Antonio.