In the main square stands the Romanesque-gothic mass of the Collegiate of S. Maria, raised over an earlier small Pieve. The first church was built in 1143 with a double nave and a square-shaped bell tower, but being of insufficient space, was placed next to the present day church. This church was erected without an apse and preserved the earlier bell tower with double and triple lancet windows; it was consecrated in 1256.
In 1517 it was assigned the title of Collegiate. The wall facing the square is adorned with high arches and three trilobed single lancet windows and a particularly lovely entrance way. The interior has a single nave with a wooden ceiling from the 1700s. Other altars were later added to the single central altar, and were transformed into the baroque style in the 1600s.

Because of the earthquake occurred in 2016, the Collegiate Church of Santa Mari is badly damaged and runs the risk of falling down.