When Emperor Phocas donated this pagan temple to Pope Boniface IV in 608, he unwittingly ensured that one of the marvels of ancient Rome would be preserved, virtually unaltered, in its new guise as the Christian church Santa Maria ad Martyres. Emperor Hadrian, an amateur architect, designed this lovely structure in AD 118–125. It has been lightly sacked over the ages – barbarians took portable pieces, Constans II stole its gilded roof tiles and, in 1625, Urban VIII melted down the portico’s bronze ceiling panels to make cannon for Castel Sant’ Angelo. Yet the airy interior and perfect proportions remain, a wonder of the world even in its own time.
Piazza della Rotonda