Gates of Rome and Aqueducts - Arch of Augustus at the Porta Tiburtina, with two inscriptions of the Aqueducts, one of Augustus, B.C. 3, the other of repairs by Caracalla, A.D. 212, the Aqueducts Marcia, Tepula, and Julia over it (the jambs of the arch are buried by the filling up of the foss-way)