Structural configuration: in a dominant position and built the foundations of a fourteenth-century oratory dedicated to San Siro - the first to be erected as a parish in March 1474 - the complex of the church of San Siro includes a church with a single nave with side chapels and polygonal presbytery; the north side is occupied by the bell tower, the south side by the sacristy and two porches are present - one at the main entrance and one at the secondary entrance. The one on the façade joins up to the rock which houses the ossuary, containing an eighteenth-century wooden crucifix. The masonry of the entire complex is plastered and painted, except for the bell tower which is only plastered. Elements of particular beauty in the interior are: the umbrella-vaulted ceiling of the polygonal apse - the only architectural testimony of the fourteenth-century church; the precious fifteenth-century wall tabernacle on the right wall of the presbytery; the high altar in polychrome marble attributed to Carloni - a significant work of sacred art from the Intelvese school of the Baroque period; the bell tower, whose four Romanesque mullioned windows, characterised by their central stone columns surmounted by a decorative capital, reveal how ancient it is (bell towers with the same motif were erected around the year 1000). Period of construction: 1476 - 16th century