Next to the Collegiate Church is the Oratory of the Holy Trinity, where on 4th May 1836 the wedding of Giuseppe Verdi to Margherita Barezzi was celebrated. The carved door, dating back to 1794, is attributed to Francesco Galli. The interior is decorated with lovely eighteenth century stuccoes and houses a splendid altar in polychrome marble (1749). Behind the altar is a bas-relief with the figure and crest of the blessed Rolando de’ Medici (1464). The apse contains Vincenzo Campi’s masterpiece of the Holy Trinity with the Saints Apollonius and Lucy) (1579).