Historical Notes. Built towards mid 1st century A.D., Porta Borsari was initially called “Porta Lovia”, because of the nearby temple of Lustral Jupiter. In medieval times it was called “Porta San Zeno” and then Porta Borsari, probably because the so-called “Bursarii”, that is to say the tax collectors with bags, levied entry and exit tariffs on goods at this gate. Only the external façade towards the countryside remains of the original construction, with its covering in late imperial style. The front is located about halfway between the line of the Republican wall in lateritious brick and the wall of Gallieno, built in 265 A.D. in various recovered material. The restoration is recorded in the long inscription on the architrave.

Architecture and Art. The complex of the gate was built from a rectangular building with two fronts with openings and with surrounding land. The hinge plates are visible in the remains of the line of the open front, made up of the bases of pillars in reinforced lateritious stone with points of tuff. Between the two fronts there was a courtyard. No trace remains of the walls that united the two fronts, just as nothing has remained of the republican gate, which must have been located in a position behind the current imperial façade.
It must be assumed that there were two guard towers alongside Borsari Gate and that there were guard rounds to join the two fronts, permitting precise and careful control of those who entered and exited from the city: a veritable fortified filter.
The plan of this complex is typically “Italic”, with two fornixes, and is one of the most ancient. Porta Borsari is therefore important as a prototype of an element of military engineering that Rome also developed in the Gallic territories and Hispanic provinces.