Walls, towers and gates Torre Obertenghi The Obertenghi tower, with a pentagonal plan, was erected in the tenth century. Its height exceeds 20 meters, as it was used for surveillance reasons. Even today we notice the Roman elements, despite the restorations it has undergone over the years. It was badly damaged by the bombings during the war, as a result, the current appearance is the result of a series of improvements.