Saint Peter’s Square is far from rectangular. From an aerial perspective it actually looks like a keyhole, an oval next to a trapezoid. The space serves as a grand entrance to Saint Peter’s Basilica at the Vatican, the heart of the Catholic Church. It is defined by a quadruple-rowed colonnade that extends from the basilica’s fagade and then wraps around an ovoid piazza, framing a central obelisk brought from Egypt by Roman emperor Caligula. The shape of the colonnade has been described as a mother’s arms that reach out from the church to embrace the worshippers who gather there.

Gianlorenzo Bernini’s design for Saint Peter’s Square, known in Italian as Piazza San Pietro, is probably his best known architectural project. It was an incredible challenge to design a space that could contain the crowds that come to the Vatican to hear the Pope, and to unify a space that contains styles from so many different periods of history. Bernini’s design included hundreds of columns and pillars, along with hundreds of statues of saints. Like the Church of Il Gesù, Bernini’s Piazza San Pietro incorporates many different architectural elements, and yet it maintains a grand and harmonious feel.