NOTES: This palace was built by Pope Gregory XIII in 1574 as a summer residence. It served as a papal residence and housed the central offices responsible for the civil government of the Papal States until 1870. It has been the official residence and workplace of the Presidents of the Italian Republic since 1946.
SOURCE: Giovanni Battista Piranesi. Vedute di Roma (Rome, [1747?-1788]), pl. 135 NOTES: This arch was erected in honour of Trajan across the Via Appia in 114 by Apollodorus of Damascus, Trajan's chief architect.