Aurelian Walls
The "quartiere" borders, to the north, with "Rione" Testaccio (R. XX), from which is separated by the stretch of the Aurelian Walls between the river Tiber and Porta San Paolo, and with "Rione" San Saba (R. XXI), from which is separated by the stretch of the Aurelian Walls between the said Porta San Paolo and Porta Ardeatina.