In Piazza Grande, also known as Piazza Vasari, stands the elegant building of the Fraternita dei Laici, a benevolent association founded in 1262, and still today at the centre of the city’s charitable activities. Begun in the late 14th century and completed between the 15th and 16th centuries, the building wonderfully combines the Gothic and Renaissance styles.

On the facade of the sixteenth-century bell tower, we can admire the extraordinary quadrant of the clock. Dated 1552, the ingenious clock is by Felice da Fossato. The bell tower houses the complex mechanism with the gearing and wheelwork which enable the various parts of the instrument to move; a meridian line served to check its precision, based on solar noon. The beautiful quadrant shows the hours, as well as the motion of the Sun and the phases of the Moon. In addition to the 12 Roman numerals, an inner circle bears 29 Arabic numerals which coincide with the days of the lunar month, while a copper disk bears geometric figures corresponding to the various positions of the Moon (treciles, quartiles and sextiles). Two metal spheres on the disk and a third one external to it respectively represent the earth, at the centre according to the Ptolemaic system still in vogue at the time the clock was built, the moon, half white and half black, and the sun. It should be pointed out that it is quite rare to find clocks of this type still existent today. In recent years, it has been perfectly restored.