If you got into a Roman cab and asked to go to St. Mary and the Martyrs, you’d likely get a blank stare from the driver. No one uses the name of the church. This is the Pantheon, and despite the altar at the back, it is revered not as a Catholic church, but as the great temple to all gods that was finished by the pagan Emperor Hadrian in 126 A.D. Though Hadrian put it up, Pope Boniface IV is the man who ensured that it wasn’t taken down. The Pantheon in Rome is on the Piazza della Rotonda.