Hours: 7:00am to noon; 3:30 to 5:30pm
Rebuilt in the 13th century in Romanesque and Gothic styles. During the Middle Ages the city fathers met here to discuss public affairs.
The interior contains columns taken from ancient classical buildings; a sculpture by Donatello; in the first chapel on the right are frescoes by Pinturicchio.
The staircase of 122 steps was built in 1348.