The Pont du Gard (literally: Gard Bridge) is an ancient Roman aqueduct bridge that crosses the Gardon River in Vers-Pont-du-Gard near Remoulins, in the Gard département of southern France. It is part of the Nîmes aqueduct, a 50 km-long (31 mi) structure built by the Romans to carry water from a spring at Uzès to the Roman colony of Nemausus (Nîmes). Because the terrain between the two points is hilly, the aqueduct – built mostly underground – took a long, winding route that crossed the gorge of the Gardon, requiring the construction of an aqueduct bridge. Built in the 1st century AD, the Pont du Gard is the highest of all Roman aqueduct bridges and is the best preserved with the Aqueduct of Segovia. It was added to UNESCO's list of World Heritage Sites in 1985 because of its historical importance.