Arc-et-Senans

Listed by UNESCO as a World Heritage site since 1982, the Arc-et-Senans Royal Saltworks is the master-work of Claude-Nicolas Ledoux (1736-1806), a visionary architect of the Age of Enlightenment. It is also a crucial monument in the history of industrial technology.  

Destined to the production of salt and decided by King Louis XV, it was built between 1775 and 1779, ten years before the French Revolution.  At the time, salt was used to preserve food products but also in the manufacture of glass and silverware, in medicine and agriculture. The State imposed a heavy tax on salt, the infamous “gabelle” which provided most of the nation’s funds. As such, salt was a major economic resource. The Royal Saltworks functioned as an integrated factory including the whole of the working community. Set in a big arch, it contained both the habitations and the production units in eleven distinct buildings.

The salt production process was especially complicated as the raw material came from 20 kilometres away. Underground pipelines were dug to bring the bittern from Salins to Arc-et-Senans. The fuel to burn it was plenty, the forest being the largest in France at the time. Once on the spot the salty water was heated in massive pans and salt was extracted as water evaporated. The salt was sold in loaves or in grains depending on its destination. Made obsolete by modern technology, the Saltworks closed in 1895. Abandoned and plundered, it was being sold for its stones when the Doubs department bought it in 1927 and progressively restored it to its original state.

It is now a unique testimony of its time.