Royal Saltworks at Arc-et-Senans

The Saline Royale (Royal Saltworks) at Arc-et-Senans, in the forest of Chaux near Besançon, France is notable as an early Enlightenment architectural project to rationalize industrial buildings and processes according to a philosophical order.

The saltworks' buildings were designed by architect Claude-Nicolas Ledoux. Construction began in 1775 during the reign of Louis XVI. The semicircular complex was planned to reflect a hierarchical organization of work. It was to have been enlarged with the building of an ideal city, but that project was never constructed.

It is worth noting that the gabelle tax was a mandatory payment on all people over the age of 8 years to buy an amount of salt per year at a price fixed by the government. This was very unpopular and is quoted as one of the reasons of the French revolution. This probably explains why this building is so grand (funded by a state monopoly). The ideal city was probably curtailed by the French revolution.

The site is preserved and managed as a monument by the Institut Claude-Nicolas Ledoux. It was added to the List of World Heritage Sites by UNESCO in 1982.