Roman aqueduct
Rome's first aqueduct was built in 312 BC, and supplied a water fountain at the city's cattle market. By the 3rd century AD, the city had eleven aqueducts, sustaining a population of over a million in a water-extravagant economy; most of the water supplied the city's many public baths. Cities and towns throughout the Roman Empire emulated this model, and funded aqueducts as objects of public interest and civic pride, "an expensive yet necessary luxury to which all could, and did, aspire".
Pont du Gard
The aqueduct bridge is part of the Nîmes aqueduct, a system built in the first century AD to carry water from a spring at Uzès to the Roman colony of "Nemausus" (Nîmes). Because of the uneven terrain between the two points, the mostly underground aqueduct followed a long, winding route that called for a bridge across the gorge of the Gardon River. The bridge has three tiers of arches, stands high, and descends a mere  – a gradient of only 1 in 18,241 – while the whole aqueduct descends in height by only over its entire length, which is indicative of the great precision that Roman engineers were able to achieve using simple technology. The aqueduct formerly carried an estimated of water a day to the fountains, baths and homes of the citizens of Nîmes. It may have been in use as late as the 6th century, with some parts used for significantly longer, but a lack of maintenance after the 4th century led to clogging by mineral deposits and debris that eventually choked off the flow of water.