The Aqua Marcia (Italian: Acqua Marcia) is one of the longest of the eleven aqueducts that supplied the city of Rome. The aqueduct was built between 144–140 BC, during the Roman Republic. The still-functioning Acqua Felice from 1586 runs on long stretches along the route of the Aqua Marcia.
Together with the Aqua Anio Vetus, Aqua Anio Novus and Aqua Claudia, it was an exceptional technical achievement and is regarded as one of the "four great aqueducts of Rome."[1]
At 91 km, it is the longest of the eleven aqueducts that supplied Rome and, although its source was further downstream than the Anio Novus, technical progress allowed the later Anio Novus to use more bridges to shorten its path instead of following contour lines as the Marcia does.
It was the first to enter Rome on arches, which were used for the last 11 km, and which were also used later combined with the Aqua Tepula and Aqua Julia.