Romanesque St James' Church was founded in the 9th century and completed in Latin-cross form in 1225, with chapels bubbling along the edges. Within the serene gloom of the interior, notable artworks include luminous sacristy paintings by Palma Il Giovane, a rare Lorenzo Lotto Madonna with Child and Saints (1546), and an exceptional Paolo Veneziano crucifix (c 1350).
Architectural quirks include decorative pillars, a 14th-century carena di nave (ship’s keel) ceiling and a 6th-century Byzantine green-marble column looted from Constantinople during the infamous Fourth Crusade.