Arch of San Damiano
The expansion of the Roman town of Carsulae was marked in the north by the city's gateway, known as the Arch of San Damiano (from the name of the nearby mediaeval church), created under the principality of Augustus (1st Century A.D).The street Via Flaminia emerged from under the arch, crossing Carsulae from the south to the north. In the urban section it was paved and bordered by pavements and gutters.
Nowadays the central fornix remains of the doorway-arch, mounted on two concrete pillars (opus cementicium) coated with large blocks of square stone and perfectly placed without mortar (opus quadratum). Originally, the central arch was flanked by two minor fornixes– lateral passages - and numerous elements of these have been recuperated during the monument's excavation. These were also used as buttresses of the central arch. The surviving fornix is round with a 5 metre span. Its height from street level is 9.2 metres and its width is 4.5 metres. Three steps form the basement of the pillars, approximately 6 metres wide. Rectangular recesses can still be observed on each of the two sides of the pillars but the function of these is unclear. They are identical in width and all positioned in the same manner. It has been hypothesised that they could host a special architectonic element, a hypothesis nevertheless which has not been confirmed by any discoveries.
San Damiano's Arch was the monumental doorway of the city, without any defensive function, erected, like so many others, during a period of peace to serve as a solemn entrance to the town of Carsulae, which was not surrounded by a city wall.
Ciotti U., et al. (1976), San Gemini e Carsulae, Milano-Roma, Bestetti Editore