The Pont du Gard, Nimes, France

A remarkable surviving example of Roman engineering and architecture

The Pont du Gard is a remarkable survivor from a previous age. Built nearly 2,000 years ago it does not look very different today than it did when first built by the Romans during the first century of the Christian era.

The Pont du Gard was built as an aqueduct to cross the River Gardon near the Roman city of Nemausus (modern Nimes in southern France). It was part of a system of canals that brought water to the city from springs 50 kilometres away. The system was carefully calculated so that the water flowed downhill at a constant gradient of 1:3000, given that the springs were only 17 metres higher than the city.

This meant that the aqueduct crossing the River Gardon had to do so at a height of 49 metres (161 feet). The result was a three-decker structure that needed to be carefully designed and built. This would have been an engineering challenge even today, with all the modern materials, computers and techniques currently available. The fact that the Roman engineers were able to solve the problem without such aids makes the final result all the more amazing.

The construction was designed to minimise the strains caused by the massive weight of the masonry. The lowest level consists of six arches…