Fontanellato, Rocca Sanvitale: the XIX century optical chamber. The circular environment, very dark, contains two systems of mirrors and a prism placed in correspondence of the ancient slits, which allow to reflect and project clearly on three screens inside the room the 180 ° image of the square in front of the fortress; the equipment, commissioned by Count Giovanni Sanvitale at the end of the 19th century, was created as a futuristic social game.
