The cathedral complex comprises several buildings constructed on the site of Roman houses and early Christian basilicas. The cathedral itself (Romanesque chancel, Gothic nave and Classical tower) boasts a remarkable main doorway decorated in Lombard style. The 12C San Giovanni in Fonte baptistery houses a superb font, a masterpiece of Romanesque sculpture. Finally, don't miss Santa Elena church (9C-12C) and the canons' cloisters with a double gallery of twin columns.