For centuries the relationships between the Franche-Comté region and the Swiss cantons were sprinkled with salt. The saltworks of Salins-les-Bains, Lons-le-Saunier and Arc-et-Senans played a significant role in supplying salt to the regions on the other side of the Jura mountains, which for a long time had no access to this indispensable mineral that is so important for the human body and for the preservation of food. Since very early times, the abbeys of Saint-Maurice d’Agaune and of Romainmôtier had rights over the Jura saltworks and received income from their yields. As salt trade developed, roads were built throughout the Jura region. They joined the road known as the “Via Francigena”, an ancient Roman route that connected Pontarlier in France to Orbe in Switzerland via the Jougne pass and that was also used by pilgrims travelling to Rome. The city of Yverdon-les-Bains, located on the outlet of the Jura passes and with a harbour on the Neuchâtel lake, soon became a centre for strategic salt trade with Bern and the Swiss cantons. From 1554 onwards, the saline springs discovered near Bex in the Chablais region are also exploited. Because its production is limited, however, this salt from the Alps cannot compete with that brought in from the French Jura region. In 1837 the saltworks of Schweizerhalle, near Basel, are opened and this does lead to a gradual decline of the salt trade between the Franche-Comté region and the Swiss cantons. The Terra Salina highlights the heritage still to be found along these historical itineraries on both sides of the border. They tell the story of salt worked to bring unity between the French and Swiss border territories.