This imposing castle dominates the main piazza in the town. Built in 1300 for the protection of Milan, it has the typical features of fortifications of the period with a moat, square floorplan and towers at the four corners. It has been restored and is now home to the Town Hall. It witnessed the tragic events which involved Filippo Maria Visconti and his second wife Beatrice di Tenda. Soon after marriage, Filippo lost interest in his wife and accused her of adultery. She was imprisoned with her supposed lover and condemned to death after a summary trial, then beheaded in the castle courtyard on the night of 13th September 1418. The event is commemorated by a stone plaque inside the castle and was immortalised by Vincenzo Bellini in the opera “Beatrice di Tenda”. The castle is now the Town Hall.