The church of Sant'Andrea della Valle was begun in 1591 by Giacomo della Porta and completed between 1608 and 1623 by Carlo Maderno. The façade added between 1656 and 1665 by Carlo Rainaldi is an elegant exercise in the Baroque style. Rising above a Latin cross plan composed of a single nave flanked by linked chapels, the dome is impressive (Rome's second largest after St Peter's). Note the extraordinary sense of depth in the frescoes by Giovanni Lanfranco.