The Castle, called Rocca for express will of the Sanvitale Counts, was founded by the Pallavicino in the 12th Century and became property of the Sanvitale family in the 15th Century, who turned it from a military fortification to a residential castle. The Rocca, with a square plan and four corner towers, is still surrounded by a large moat, full of water, that makes it unmistakable in the varied and rich panorama of castles dotting the territory of Parma. The whole history of the fortress and the town is linked to the Sanvitale who were its feudatories, a continuous and secular link with Fontanellato, which was interrupted only in 1948, when the last Count Giovanni sold the manor to the Municipality and with him the local branch of the family became extinct. The fortress then became the seat of the Town Hall and the Museum, a noble house that has been preserved intact over time, and that allows the visitor to immerse himself in furnished environments with paintings, furniture, furnishings, frescoes that have maintained their charm for more than 500 years. The most precious jewel of the Rocca of Fontanellato is the "Room of Diana and Acteon", frescoed by Francesco Mazzola called Parmigianino (Parma 1503-Casalmaggiore 1540), one of the greatest masters of Italian Mannerism. A unique and original feature is represented by the Camera Ottica, wanted by the Sanvitale at the end of the 19th Century: a system of mirrors captures the direct image of the square outside and projects it on a table.