Pope Clement XI in 1711 over a fountain by Filippo Barigioni .  http://en.wikipedia.org/wiki/Obelisks_in_Rome      Piazza di Montecitorio Originally from Heliopolis . Brought to Rome by Augustus in 10 BC with the Flaminio obelisk to form the gnomon of a sundial on the Campus Martius . Found in 16th century but reburied.