On the site where this majestic church now stands there was once a small church called St Ambrogio, which Pope Sixtus IV had granted to the people of Lombardy who lived in the area. When St Charles was canonized, they decided to rebuild it and call it by the names of the two patron saints of Lombardy. The magnificent cupola and apse are by Pietro da Cortona, and the altarpiece portraying the two saints is by Carlo Maratta. St Charles' heart is preserved in the chapel in the corridor behind the altar. The interior has a Gothic architectural style, which resembles the style of the Duomo in Milan.
- Open Hours: Monday to Sunday from 07:00 AM to 12:30 PM, Monday to Sunday from 05:00 PM to 07:30 PM
- Nearest Train: Spagna