Identify.

Arch of Septimius Severus, 203 CE, commemorates victory of the Parthians (triumph in 202 CE, gone under semi-permanent arch in this location), much larger than Arch of Titus, triple bayed arch (arcuated openings, 1st surviving example in Rome), panels over side bays (decoration), 4 free-standing columns on pedestals decorated with Parthians and Roman soldiers