Not far from the Dessoubre and Doubs valleys, the Franche-Montagne region was formerly the haunt of smugglers. Some of the sites on the immense plains of northern Jura will make those who suffer from vertigo shudder, such as the iron ladders embedded in the rock, up which you have to climb to get to the viewing platform. Solidly made and equipped with double bars and handrails, they make the climb up to a hundred or so metres/yards above the Doubs gorges less perilous than may seem.