Set at 564 metres above sea level, the Ratti Fort is the furthest military outpost set to the East of the city. It was built in only four years (1833-37) because of its strategic importance to the Sabaudo Kingdom of that period. Spread over some 260 meters and three floors it is almost as though the fort was a part of the mountain itself. It was extensively used during the First World War for captured Austrian prisoners of war. Although the fort is abandoned it can be easily reached form the city by a nature trail dotted with information boards.