A magnificent example of Lombard Romanesque style, this basilica, founded by Saint Ambrose in the 4C, is preceded by a superb atrium. Two bell towers frame the façade, which is pierced with arches. Inside, a beautiful Romanesque-Byzantine ambo (pulpit), and an altar facing covered with golden plates, a masterpiece of the Carolingian period (9C.). Beautiful mosaics from the 5C. Ambrose, the inventor of the calendar and of Milanese liturgy, is resting in the crypt with Gervasio and Proteo.