The imposing seventeenth-century façade of Carlo Maderno gives an idea of ​​the exceptional dimensions of St. Peter's Basilica, still today one of the largest churches in the world. The primitive Basilica of San Pietro, a building comparable in size to the present, was built around 320 by Emperor Constantine in the place where, according to tradition, the apostle Peter was buried.

From the middle of the fifteenth century began that long process that, in about two hundred years and with the help of many artists (Bramante, Michelangelo, Bernini), would have led to the complete reconstruction of the primitive Constantinian basilica.

The imposing facade, 115 meters long and preceded by a staircase with three shelves, has pilasters and Corinthian columns and is surmounted by an attic crowned by thirteen colossal statues. At the centre is the Loggia delle Benedizioni: from here the Pope blesses the faithful on the most solemn occasions and the election of each new pontiff is announced to the world.