Built on a basilica type plan, this is one of the most attractive Romanesque churches in northern Italy, truly representative of the Lombard style. The exterior, in particular, is remarkable for the decor of Lombard bands and arcading. There are wonderful bronze doors and, inside, above the splendid main altar is a triptych by Mantegna (1459). The odd multicoloured statue of "St-Zeno laughing" shows the town's patron saint (buried in the crypt with Cosmo and Damien) on a happy day.