Located ouside Porta Ninfina, the bridge allows us to cross the Formale- Catena ditch. It is composed by piedritti in opera poligonale di blocchi calcarei, placed directly on the rock. The arch is realized with the conci di tufo a superficie bagnata. The employment of two different materials as well as different constructive techniques, could be due to a later restoration of the arch during Augusto. The most recent interpretations, date the structure to the beginning of I cent. BC. The tombinamento of the ditch,  is an obstacle to catch the original architecture of the monument.