Via di Mercurio is a short yet primary street running north to south in the northwestern section of Pompeii. I presume its namesake is Mercury, the Roman god of commerce. In the background, at the intersection of Via delle Terme, is the Arch of Caligula. However, some sources call this red brick structure the Arch of Tiberius, Augustus, Nero or Mercurio. It was a portal to the Tempio della Fortuna Augusta.