Saint Peter's Square is located directly in front of St. Peter's Basilica in Vatican City, the papal enclave within Rome (the Piazza borders to the East the rione of Borgo).
At the center of the ellipse stands an Egyptian obelisk of red granite, 25.5 meters tall, supported on bronze lions and surmounted by the Chigi arms in bronze, in all 41 meters to the cross on its top. The obelisk, of the 13th century BC, was moved to Rome in AD 37 by the Emperor Caligula to stand in the central spina of the Circus Gai et Neronis, which lay to the left of the present basilica. It was moved to its current site in 1586 by the engineer-architect Domenico Fontana under the direction of Pope Sixtus V; the engineering feat of re-erecting its vast weight was memorialized in a suite of engravings. The Vatican Obelisk is the only obelisk in Rome that has not toppled since ancient Roman times. During the Middle Ages, the gilt ball on top of the obelisk was believed to contain the ashes of Julius Caesar. Fontana later removed the ancient metal ball, now in a Rome museum, that stood atop the obelisk and found only dust. Though Architect Bernini had no influence in the erection of the obelisk, he did use it as the centerpiece of his magnificent piazza.
The paving is varied by radiating lines in travertine, to relieve what might otherwise be a sea of cobblestones. In 1817 circular stones were set to mark the tip of the obelisk's shadow at noon as the sun entered each of the signs of the zodiac, making the obelisk a gigantic sundial's gnomon. Below is a fabulous view of St. Peter's Square from the cupola (the top of the dome) which was taken in June, 2007.