We don’t know much about this straight “Roman” path. From Villard D’Héria, a village to the south of Moirans-en-Montagne, where the remains of a temple and of a cult and thermal complex can be found in one of the most remarkable Gallo-Roman sites of southern Franche-Comté, since the 2nd century, the main axis of this path runs from the Le Gouillat hamlet in the municipality of Charchilla, to the Sous la Razée hamlet in the municipality of Maisod.
From there, a path branches off towards a set of inhabited areas, around and on Mont River, another Gallo-Roman site near Champagnole. A second path crosses over the Ain and joins up with the other North-South roads towards Salins, Besançon or Lons-le-Saunier. This ford was replaced by a bridge during the 13th century, which was often destroyed but always rebuilt up until the Pont de la Pyle which currently bridges the gap over the Vouglans lake.