Naples is the third-largest city in Italy after Rome and Milan, but during its nearly 3,000-year history, it has never been the favorite child of the Italian peninsula. Accustomed to making it on its own, it has grown robust, but it’s a bit rough around the edges. The streets are based on an ancient Greco-Roman order: Three parallel streets running east-west are intersected by a series of smaller streets running north-south, of which one is Via Duomo, where the medieval Il Duomo, also known as Cathedral of the Assumption of Mary, rises over the rooftops. From the harbor of the Bay of Naples, you can walk down Via Duomo into the heart of the city and sit down with a coffee at Caffè del Duomo to study the public square in the cathedral’s shadow. Each afternoon, the square turns into a soccer pitch for the young boys of the neighborhood, as they kick …