Temple
Ad Sanctum Petrum
Sankt Peter
Listen to the story
Ad Sanctum Petrum, 'at Saint Peter's', is the old basilica on the Vatican, and the map writes its name in red. The drawing is a house-shaped building set on a raised base, and archaeology has confirmed such a podium, although the church of Constantine had a transept that the picture lacks. Building began around 320, on the site of a racecourse begun by Caligula and finished by Nero. A tiny sign links it to the Via Triumphalis, most likely standing for one mile: the map keeps no fractions, so it could not write the distance to the Ponte Sant'Angelo, some six hundred and fifty paces.