The collegiate church of Santa Maria Maggiore dates from the fifth century being built over a pagan temple dedicated to Venus. The renovations in 1200 give it the current Romanesque-Gothic appearance. The large rose window was built in the early fourteenth century. The church preserves valuable works. A small masterpiece is the Madonna of Constantinople, a polychrome wooden sculpture inserted in a large stained altarpiece realized by a Lazio artist and donated to the chapel. The bell tower was added in 1394.