The cathedral dates mostly from the 12th and 13th centuries; the main tower is from the 16th century. The statues on the portal represent everybody from the Queen of Sheba to David at the harp. The tympanum depicts Christ Enthroned. The stained-glass windows from the 12th through the 16th centuries have made the cathedral famous. The oldest one illustrates the martyrdom of St. Vincent; the most unusual is of St. Christopher with the head of a dog. The 12th-century nave, a landmark in cathedral architecture, is a work of harmonious beauty.