At the center of Saint Peter's Square stands a 25.5 meter tall ancient Egyptian obelisk, 41 meters high including its added base. This obelisk is over 4000 years old and was brought to Rome from Alexandria by Emperor Caligula in 37 AD.
The obelisk was removed from the “Circus of Nero” in Rome and placed at the center of the square under the order of Pope Sixtus V in 1586. The re-erection of the obelisk required a work force of some 900 men and almost 100 horses and took over a year to complete.