From the 1st century B.C., the Pyramid of Caius Cestius, about 36m (120 ft.) high, looks as if it belongs to the Egyptian landscape. It was constructed during the "Cleopatra craze" in architecture that swept across Rome. You can't enter the pyramid, but it's a great photo op. And who was Caius Cestius? He was a rich magistrate in imperial Rome whose tomb is more impressive than his achievements. You can visit at any time.