Take a tour of the San Leo Fortress in Italy - part of the World s Greatest Attractions travel video series by GeoBeats. The fortress of San Leo, northeastern Italy, occupies a prime defensive location. The main building cuts a knife-thin profile across the sheer cliff-top. The fortress was the final prison for Count Cagliostro, who was put to death by the Spanish Inquisition. The cliff, which has provided the fortress with its key defense, has also caused its structural problems.