The large monumental complex of S. Abbondio has ancient origins: probably belonging to the Benedictines, in the 13th century it passed to the Humiliati, then to the Theatines and, finally, was transformed into a parish church in 1804.

The interior of the church features 16th-century paintings by great artists such as O. Samacchini, Malosso and G. Campi, while the monumental sacristy houses numerous paintings by Massarotti. 

Adjacent to the church is the Santuario Lauretano, built in 1624 at the behest of the nobleman Giovan Pietro Ala as a copy of the Holy House of Loreto. It houses the Black Madonna, a sculpture that has been the object of great devotion, especially since the plague of 1630. 

The Bramante cloister, dating back to 1511, is particularly elegant, with rooms decorated with historical and mythological subjects.

On the upper floor of the cloister, where the ancient apartment of the prior of the Humiliati once stood, there is a museum that houses the ancient collection of ex-votos, precious liturgical furnishings and works of particular importance.
The parish archives contain the baptismal register with the entry relating to Claudio Monteverdi.