The church of San Gregorio Magno was built on land owned by Pope Gregory Magnus and was rebuilt by Gregory II at the start of the 8th Century. The shape of the church dates back to 1635 when the façade and stunning flight of steps were added. The vaults are a masterpiece with frescoes portraying the Glory of Saints Gregory and Romualdo and the chapel of Saint Gregory. There are three chapels outside built by Cardinal Baronio and they are dedicated to Saint Andrew, Saint Silva and Saint Barbara.