It is the oldest church of Castel Madama as shown by documents of the year 958, and appears in the "Summary of the Tiburtina" in 992. It was built as a place of worship for the pastors and the church is in the shape of a gabled hut with a single aisle. In the late sixteenth century the Zuccari Brothers realised the fresco of the "Divi Quirici et Judictae sacellum" on the wall behind the altar. Inside is the altar of St. Isidore, patron of ploughmen. Every year during the feast of the holy peasants competed in the "race of the groove."