An impressive brick construction, this castle was built by Galeazzo Visconti between 1360 and 1365. Originally a vast square plan, only the north wing survives. The huge inner courtyard has arcades and a loggia with twinned bays. The castle is home to the municipal collections, rich in archaeological objects and especially paintings. Note also the sumptuously decorated ceiling in room 2 (the Sala azzurra) of the archaeological museum (ground floor).