Piazza San Pietro (St Peter's Square) is, quite simply, one of the most beautiful spaces in Rome.
The twin colonnades were commissioned by Pope Alexander VII (r. 1655-67) and built by Gian Lorenzo Bernini (1598-1680) between 1656 and 1667, a gigantic and costly undertaking that nearly bankrupted the papacy. Bernini designed the gently curving colonnades, each of which is made up of four rows of columns (each 13 m high), to symbolise, in his words, 'the maternal arms of Mother Church'.
The colonnades are crowned with the coat of arms of Pope Alexander VII and the statues of ninety-six saints and martyrs, the work of members of Bernini's workshop.
Embedded into the cobblestones of the piazza, between the fountains and the obelisk, are two marble discs, each bearing the words 'centro del colonnato'. Stand on one of the discs, look at the nearest colonnade, and you will see that the four rows of columns line up perfectly, creating the illusion that there is only a single set!
Two colossal statues stand at the base of the steps leading up to St Peter's Basilica; St Peter (1840) is the work of Giuseppe de Fabris (1790-1860), while St Paul (1838) is by Adamo Tadolini (1788-1868).