Built in 1250, it was the palace where justice was administered. It is a large building with battlements. The façade overlooking the square is made up of a 16th century portico with shops. The upper part, lit by the big three-mullioned windows you can see from outside, contains a large space now used for exhibitions. The Tower was built in 1472 from a project by Luca Fancelli. The clock was added in 1493. Designed by Bartolomeo Manfredi it shows the phases of the moon, the best days for doing certain tasks and the position of the sun in relation to the signs of the Zodiac. In 1639 the statue of the Immaculate Virgin was placed in the niche under the clock-face.