Porta Maggiore was built by Claudius in AD 52. Then, as now, it was a major road junction under which passed the two main southbound roads, Via Prenestina and Via Labicana (modern-day Via Casilina). The arch supported two aqueducts – the Acqua Claudia and the Acqua Aniene Nuova – and was later incorporated into the Aurelian Wall.
