Barrage Vauban

The Barrage Vauban is a covered bridge and defensive weir on the River Ill at Rue de Zurich, just upstream of La Petite France in Strasbourg, Grand Est, France. It was built between 1686 and 1700 after Louis XIV annexed the free city in 1681, under the direction of the military engineer Sébastien Le Prestre de Vauban, who strengthened Strasbourg's fortifications. The structure is a long arched bridge of pink Vosges sandstone with a gallery above, fitted with sluice gates that could be lowered to flood the southern approaches to the city in case of attack, turning the surrounding meadows into a barrier to besieging armies. The covered gallery, originally the main military passage, is lined with arches that look onto the river. After the old fortifications lost their function in the 19th century the dam was kept as a monument, and in the 20th century it was restored and used as a display space for sculptures from the cathedral and the city's museum collections. Weathered statues from the cathedral have been kept there, and visitors can walk through the lower gallery to see a small sculpture display and the mechanism of the dam. The flat roof forms a terrace that is open daily and gives one of the best views of the Ponts Couverts, the medieval towers and the red roofs of La Petite France, as well as of the Ill flowing through the arches. The structure stands as a monument to the military engineering of the Ancien Régime, and its preservation shows how Strasbourg's defences were converted into public space. The weir also illustrates the French military approach to the city after annexation, when Vauban combined the existing medieval walls with new bastions, a citadel built from 1682 and water defences. Visitors who combine the terrace with a walk along the Ill can trace how the river was used to protect the southern side of the old town, and how the quarter around it later became a residential and tourist area.