Rome - Arch of Janus Quadrifrons Arco di Giano

This marble structure in the Via del Velabro, in front of the church of San Giorgio in Velabro, was long thought to be part of the temple of Janus. In fact this was a covered passage (Janus) with openings on four sides (quadrifrons) of a busy street intersection in the commercial quarter of Rome. The arch was built in the Constantinian period, incorporating material from earlier buildings. During the Middle Ages it became a strong point of the Frangipane family.