In the Renaissance style although subsequently altered during the Baroque period, the church has 15C frescoes by Pinturrichio (first chapel on the right), two tombs by Sansovino (in the chancel), and two paintings by Caravaggio - the Martyrdom of St Peter and the Conversion of St Paul (first chapel to the left of the chancel) – plus the Chigi Chapel (second on the left) by Raphael.