Introduction to Cathedral Square: Piazza del Duomo is adjacent to Piazza del Duomo and is named after the Cathedral of San Gimignano on the square. It is also the religious and political center of the town. Piazza Duomo was built in the first half of the 13th century, the golden age of San Gimignano's history. There are many ruins around the square, including palaces and cathedrals with frescoes, as well as 4 of the 14 remaining towers.