The Church of St. Sigmund dates back to 1463, when its construction was commissioned by Bianca Maria Visconti on the same spot where the church in which she married Francesco Sforza in 1441 once stood. The building is one of the architectural jewels of the Lombard Renaissance before the coming of Bramante.

The interior began being painted in 1535 and it is one of the most harmonious decorative complexes of sixteenth-century Mannerism in northern Italy, and the central part of the transept is occupied by spectacular wooden choir stalls. The cloister of the old convent sits adjacent to the church.