Porta Camollia was not the only fortification built to defend the northern side of the city, always the most subject to attacks from the rival city of Florence. These two other fortresses were the Torrazzo di Mezzo and the Antiporto.
The outermost gate of the city, also known as "Portone" (gate) or "Portone dipinto" (painted gate), now commonly called "Antiporto di Camollia", according to documentary sources, was begun around 1270.
It has long been believed that there was a fresco by Simone Martini inside the building. However, several petitions over the years, as early as 1300, have never highlighted works in this regard.
The works of Giuseppe Nasini were absolutely real: in this grandiose portico he represented a sort of magical forest with the branches of the plants that, intertwining, formed circles with the coats of arms of the 17 districts inside. Despite the bombing of 1944 and the considerable damage suffered, these coats of arms of the districts survived, but what was not damaged by the war, was damaged did the man. With an "inappropriate" restoration not many years ago, these drawings were definitively cancelled.