De la grande saline de Salins-les-Bains à la saline royale d’Arc-et-Senans UNESCO World Heritage Sites

The salt works at Salins-les-Bains and the Royal Saltworks at Arc-et-Senans are two production sites connected by an underground pipeline system stretching over 20 kilometers apart. The first facility draws brine from natural springs, while the second processes this water and extracts the salt through evaporation and crystallization.

Salt extraction at Salins-les-Bains started during the Middle Ages, using natural brine springs in the area. In the 1770s, architect Claude-Nicolas Ledoux designed and built the new saltworks at Arc-et-Senans as a model industrial facility for the French crown.

These sites show how salt production shaped the communities and daily rhythms of the Jura region for generations. The layout of buildings and facilities reflects the central role this industry played in local life and commerce.

Visitors can explore both sites through guided tours that explain salt production methods, with museums showing how the work was done. Coming in spring or fall offers pleasant weather and fewer crowds than summer peak season.

The brine pipeline was engineered so that salty water flowed downhill through underground tunnels, saving energy and keeping the distant saltworks supplied without pumps. This network was a remarkable engineering achievement that operated for over two centuries.