Built between 1617 and 1644 in order to house the image of a miracolous 16th century Madonna of the Grace, still hanging on the altar, the oratory was designed in Baroque style by G.B.Magnani and G.Rainaldi. 
Shaped around a central plan, it boasts Rococo decorations and frescoed by Sebastiano Galeotti painted in 1715 as well as panels by F.Natali and pendentives by Sebastiano Galeotti with trompe-l'oeil perspectives and fictive architecture. Two side chapels house two paintings dating back to the 18th century.