An aqueduct! Three arcades rows building, over the Gardon's valley... In the 1st century, the little sacred spring called Nemausus wasn't enough for the huge population of Nîmes. The aqueduct forwarded the water, from Eure's sources in Uzès to Nîmes' districts, going underneath the capitol, leading to the |i]castellum divisorium|/i], aka the "water tower". From that point, water passed below the Magne tower and finally get to thermae and different pools.
With its 52 arches, its 50 meters long and its daily flow of 20000 cubic meters, the bridge is a real masterpiece! But people forgot it from 4th century... they came from all the area to grab some stones in order to build their own houses! Then in the 19th century, emperor Napoleon III undertook the restoration. An inscription found in Nîmes' thermae says the aqueduct was raised by Augustus' favourite, Vipsanius Agrippa.