Ancona
The oldest part of town straddles Colle Guasco, the hill above the port. On the peak stands Ancona's finest church and its most obvious landmark, the Medieval Cathedral of San Ciriaco, a pleasing mix of Romanesque and Gothic. The picture shows the impressive facade, and from the piazza are wonderful views of the city and port.
 
The austere interior is picked out with exotic Byzantine touches, a painted wooden roof in the form of an upturned boat, and a soaring 12-sided cupola - a place to linger in out of the summer heat. In the crypt you can glimpse the remains of an ancient pagan temple that provided the foundation for the church.
 
To see the rest of the best, start your walk from the bottom of Corso Stamira down by the ferry docks. After noting the Venetian-Gothic facade of the ruined church of San Agostino cut across to nearby Piazza della Repubblica where Corso Garibaldi and Corso Mazzini start (the other two Corsi that complete the city's trinity of parallel main streets).