This much-altered 6th-century church is dedicated to the apostles James and Philip, whose relics are in the crypt. Its most obvious attraction is the portico with its Renaissance arches and the two-tier facade topped by 13 towering figures. Inside, the flashy baroque interior was completed in 1714 by Carlo and Francesco Fontana. Highlights include the ceiling frescoes by Baciccia and Antonio Canova’s grandiose tomb of Pope Clement XIV.
Surrounding the basilica are two imposing baroque palazzi: at the end of the square, Palazzo Balestra, which was given to James Stuart, the Old Pretender, in 1719 by Pope Clement XI, and opposite, Palazzo Odelscalchi, with its impressive Bernini facade.