Although it has lived many lives under several different occupiers and been restored many times, this fortified castle is the masterpiece of Milan’s two most powerful medieval and Renaissance dynasties, the Visconti and the Sforza. The Visconti built the castle (and the Duomo) in the 14th century before the Sforzas married into their clan, eclipsed their power, and took their castle in the 1450s, turning it into one of the most gracious palaces of the Renaissance. Sforza capo Ludovico il Moro and his wife Beatrice d’Este also helped transform Milan into one of Italy’s great centers of the Renaissance by commissioning works by Bramante, Michelangelo, and Leonardo da Vinci. Its most recent restoration was at the hands of architect Luca Beltrami at the end of the 19th century, and it opened as a museum in 1905.

Today the castle houses a dozen museums and archives, known as the Musei del Castello Sforzesco. Many of the Sforza treasures are on view in the miles of rooms that surround the castle’s labyrinthine courtyards, stairways, and corridors. They include a pinacoteca with works by Bellini and Correggio plus Spanish Mannerists Ribera and Ricci. The extensive holdings of the Museo d’Arte Antica include the final work of 89-year-old Michelangelo; his evocative, unfinished “Pietà Rondanini” (rondanini.milanocastello.it; tel. 02/8846-3703), which was discovered in his Roman workshop at the time of his death in 1564. It’s displayed in an area of the castle known as the Spanish Hospital, once used as an infirmary by the castle’s Spanish garrison in the late 1500s.