The arcade running south from Piazza Vecchia belongs to this 12th-century civic palace — one of the oldest town halls in Lombardy. Look for the 1798 sun meridian laid into the floor and the disk in the ceiling above through which sunlight strikes it at noon.
Inside (when exhibitions are on) there are frescoes from the 1300s and 1400s, including Bramante's three philosophers from 1477. A statue of Torquato Tasso stands near the Caffè del Tasso at the corner.