Porta Borsari was the main gate of the Roman City on Via Postumia, the ancient highway connecting the Tyrrhenian Sea to the Adriatic Sea.
It was built in the 1st century AD and was called Porta Iovia due to its proximity to the ancient temple dedicated to Jupiter lustralis. It became "Porta Borsari" in the Middle Ages, when customs officials demanded duties by stopping the incoming goods. Made of tuff and bricks, originally it was a building with a central courtyard and elegant decorations. Porta Borasari had to be majestic, so that travellers could understand the importance of the city they were about to enter.
Today, only the external façade is preserved and it has a structure arranged over three levels, with two arches flanked by semi-columns with Corinthian capitals. At the centre you can notice the inscription wanted by emperor Gallieno in 265 AD for the extension of the urban walls.
It was a source of inspiration for the great Renaissance architects such as Michele Sanmicheli, and was also depicted on medals of the fifteenth century.