The Canal de Marseille is a major source of drinking water for the city of Marseille, the largest city in Provence, France. The canal's length along its main artery is 80 kilometres (50 mi) - though there is an additional 160 kilometres (99 mi) of minor arteries - and it services the entire district of Marseille. It took fifteen years of construction under the direction of engineer Franz Mayor de Montricher, and opened on July 8, 1849. It represents a significant achievement in nineteenth century engineering, combining bridges, tunnels, and reservoirs to create a canal over mountainous terrain.