Constructed of shelly limestone, the Pont du Gard is an ancient Roman aqueduct that is still standing today, crossing the Gardon River in southern France. Built circa 40 CE, the three-tiered bridge was added to the list of UNESCO World Heritage Sites in 1985.
Slap On Some Aqueduct Tape & Call It A Day
Details are understandably a little spotty roughly 2,000 years later, but the architect of the Pont du Gard is generally credited as Marcus Vipsanius “Big Marc” Agrippa, son-in-law and stooge of Emperor Augustus. Agrippa was the senior magistrate responsible for the water supply to Rome and its many colonies. Historians estimate that construction of the bridge took about 15 years and employed roughly 800 to 1,000 workers.
As the Roman Empire slowly fell apart, so did the Pont du Gard. From the 4th Century CE onward, maintenance of the aqueduct was neglected—invading forces and local uprisings kept Roman forces plenty busy. Debris, plant roots, and mineral deposits combined to create deposits up to 20 inches thick on each wall. At its peak, the Pont du Gard carried an estimated 44 million gallons of water a day to the citizens of Nîmes, but this flow had slowed considerably by the 6th Century CE and the aqueduct fell out of use.
The Pont du Gard continued to serve as a toll bridge for centuries, however. In the 13th Century CE, the King o’ France gave locals the right to collect tolls from those using the bridge, with the caveat that these same locals were in charge of maintaining the bridge.
Three centuries later, lead Huguenot Henri, Duke of Rohan (“Big Hank”) and his traveling soldiers caused significant damage to the bridge when they hauled their artillery across it on their way to battle against French royalists. To fit his carts and cannons through the bridge’s narrow spaces, he had one side of the second level of arches cut away to only a third of their original thickness. Unsurprisingly, this severely compromised the Pont du Gard’s structural integrity.
Restoration efforts began in 1703, commissioned by local authorities, but by 1835 the bridge had deteriorated so badly that it was nearing collapse. Napoleon III visited the site in 1850, and set architect Charles “Big Chuck” Laisné to the task of repairing it, with funds provided by the Ministry of State. Following further restoration efforts, the most recent of which concluded in 2000 CE, it continued to be used as a footbridge across the Gardon.
A Marvel of Engineering
The Pont du Gard’s highest tier stands over 160 feet above the surface of the Gardon River. The upper deck of the three-level structure descends only about one inch from one side to the other, showing the exceptional precision of which Roman engineers were capable, despite the limited technology of the time.