St. Peter's Square Obelisk

A 25-metre red granite obelisk brought from Heliopolis by Caligula in 37 AD to decorate his circus on the Vatican Hill — the very arena where Saint Peter was martyred and where, according to tradition, his blood was spilled. It's the only Roman obelisk that has stood continuously since antiquity, never falling. Pope Sixtus V had Domenico Fontana relocate it to its present spot in 1586; the operation took 13 months, used 900 workers and 140 horses, and was conducted under threat of death for any spectator who broke the silence.