The church of San Martino was built in the 12th century on the site of a Romanesque building, which can still be recognized by the arches on the right, next to the Chapel of the Crucifixion. The bell tower is also of Romanesque origin; It has three-arched windows in the uppermost part, the columns of which are decorated with capitals depicting animals, heads, cylindrical elements and palm trees.
The interior was repainted in 1922. The altars and the choir are decorated with multi-colored stucco work - some by Carlo Terugia (1654). The main altar, made of gilded wood, with decorations in mock marble, dates from the 18th century. According to tradition, the openwork copper lamp in front of the altar was a gift from St. Charles Borromeo. The sacristy with three walnut cupboards with ornate columns from the 17th century is also interesting.
The church was restored in 1984-91. The excavations brought to light part of the apse (8th/9th century). Multicolored stucco fragments from the 7th/8th centuries were found in the choir. Century and fragments of frescoes from the late 15th century were discovered on the walls of the nave.