A monumental arch of the Etruscan walls (3rd century B.C.), it is the important southern gate into the city, opposite the Arco Etrusco of Piazza Fortebracci. On the occasion of the construction of the Rocca Paolina, Sangallo demolished and recessed the upper part of the gate, pushing it back by four meters into the façade of the fort. Built in travertine, like the walls, it has a vault arch decorated above by a loggia from which jut out five sculptures, perhaps Zeus between the Dioscuri with their respective horses. Above and below the loggia runs the Latin inscription COLONIA VIBIA and AUGUSTA PERUSIA.