Porta del Popolo

The outer face was commissioned by Pius IV from Michelangelo, who passed the work to Nanni di Baccio Bigio; it was executed between 1562 and 1565 on the model of the Arch of Titus, and its four columns came from the old St Peter's. The statues of Peter and Paul are by Francesco Mochi, 1638. The inner face is by Gian Lorenzo Bernini, made for Alexander VII for the arrival of Christina of Sweden on 23 December 1655, an event recorded by the inscription Felici faustoque ingressui MDCLV. it.wikipedia notes that the service door still carries the older spelling Campo Marzo, which was the rione's name until the Napoleonic period.