The Gouille au Cerf tunnel

Notice the entrance to the Lézat tunnel, also known as the Gouille-au-Cerf tunnel. This tunnel is 1,742 meters long and was built between 1906 and 1911. With 9 viaducts and 18 underpasses, it is one of the longest structures on the line between Morez and Saint-Claude, the last section of the Andelot - La Cluse line, which opened on 10 August 1912. Today, the line is known as the “Ligne des Hirondelles” (Swallows’ line) due to the heights of its viaducts and its winding path through the Jura mountains.
Learn more about the “Ligne des Hirondelles”: www.saint-claude-haut-jura.com/ligne-hirondelles.html