Start your adventure along the Grande Traversée du Jura by mountain bike at Mandeure, a town south of larger Montbeliard that boasts the ruins of a Gallo-Roman theatre. On this first stage, follow the Doubs River to the historic fortified small town of Saint-Hippolyte, nestled at the confluence of Doubs and Dessoubre. The reward for the physical and technical challenges on this first stage is beautiful landscapes, best appreciated from the viewing points (belvédères)

Leaving Saint-Hippolyte, this GTJ by MTB stage starts with a long climb, following a former Roman road up to the Plateau de Maîche, with lovely views over the Doubs Valley. Then the route plunges you back down to the river gorges and a spot beloved of anglers. Give your legs a rest on the riverbank, admiring the fly-fishermen’s skills, ‘tickling’ the trout and rainbow trout teeming in the waters.

At Goumois, crossing the river, you enter Swiss territory. For a few kilometres, the GTJ by MTB stays in Switzerland, taking you through the wild Gorges du Doubs. This stage is magical but challenging. The names of certain spots speak volumes; at the Echelles de la Mort (‘the Ladders of Death’), get off your bike to experience the thrill of smugglers who used to climb the cliffs here to secretly carry goods across the border. Before reaching Fournet-Blanche-Roche, take on an extra few hundred meters to appreciate the extraordinary views over the Doubs Valley from the Belvédère de la Cendrée.

The GTJ by MTB ("GTJ VTT") has taken you up to the Plateau de Maîche, with verdant pastures where Montbéliarde cows graze, their milk producing Comté cheese. The way now takes you along ledges perched above the Doubs Gorges, providing several viewing points over the Saut du Doubs waterfall and its pools. Entering the Pays de la Saucisse (Sausage Country – the nickname from the little sausage-producing town of Morteau), admire the magnificent Franche-Comté farms with their distinct hearths (tuyés), sometimes with renowned local smoked meats drying outside: Morteau sausage, dried ham and rustic bacon – specialities to try on a picnic or at a meal.

Soon, the GTJ VTT mountain biking route leads you to the town of Pontarlier, an entry point to the Parc Naturel Régional du Haut-Jura. Then a technically-challenging path heads up to the Château de Joux, looking proudly imposing on its rocky outcrop dominating a deep narrow valley, or cluse. The track wends its way through shady, majestic spruce and fir making up the Jura forests around here, as far as the resort of Métabief.

Métabief was made for mountain biking. It was one of the first ski resorts to open its ski slopes to mountain bikes in summer and provides the perfect opportunity to try out downhill mountain biking. At all events, whether by bike or by chair lift, make sure to get to the summit of the Mont d’Or, at 1,463m the roof of the county of Doubs, with breathtaking views across to neighbouring Switzerland and down to the Alps. After that, glide over to Mouthe and visit the source of the Doubs River, which has served as your companion since Mandeure. You’ll encounter a ski jump, recalling that you’re in a part of France specializing in Nordic ski activities.

Chapelle des Bois, with its cliff, lake and peat bog, has something of a Scandinavian feel to it. Following forest tracks, you cross the high-altitude woods of Le Risoux and Le Massacre either side of the ski resort of Les Rousses, where protected species such as capercaillie and lynx are king. Unspoilt, authentic nature has been preserved here. The GTJ by MTB ("GTJ VTT") enters the territory of the Haut-Jura, the landscapes changing, becoming more mountainous.

Approaching the village of Lajoux, the crests of the Haut-Jura appear, along with an extremely beautiful view of the Col de la Faucille pass. In the village, the Maison du Parc will help you understand the terrain you’ve covered so far on your GTJ by MTB ("GTJ VTT") adventure. Crossing the Hautes Combes is a delight, given both the gentle route and the beauty of the natural setting, the easy paths leading you between combes and light woods. All along, the Jura’s summits to the east guard the way, while the Chalam Crest provides a magnificent view onto the geology of the Cirque de Chezery from the so-called Lion frontier stone. You enter the Auvergne-Rhône-Alpes Region and the county of Ain via a lovely descent.

The GTJ mountain biking route ("GTJ VTT") cycle route now leaves the Haut-Jura area as you enter the county of Ain and the very beautiful Retord Plateau. As you descend into the valley that cuts the mountains here in two, consider the staggering natural forces that shaped these landscapes. Around the Plateau de Retord, gentle, tranquil nature is your sole companion. If you are lucky enough to cross the plateau in June or July, you can enjoy the spectacle of the narcissi meadows in flower, their scent filling the air. Around here, these flowers are picked to extract their essence, which goes into perfumes made by famous names.

You reach the heart of the Haut-Bugey here. In this remote area, the population drain has been halted by concerted efforts to keep community support and traditional life in these mountains thriving. The locals are proud of the way they’ve maintained their traditions in producing Comté cheese. The Grande Traversée du Jura cycle route here leads you through pastureland and forests via small paths and forest tracks. You finish this stage at one of the last high points on your adventure.

Make the most of this penultimate stage of the Grande Traversée du Jura by MTB to admire certain distinctive features that can help sum up your adventure. Follow the track to the Observatoire de la Lèbe, wayside panels giving details on the night skies and planets. In the exceptionally beautiful Gorges de Thurignin, admire one last time the distinctive geology that has marked your way along the "GTJ VTT". The little town of Culoz marks the end of the route. At the foot of the mighty Grand Colombier Mountain, it sits beside the Rhône, the natural frontier here with the once-separate state of Savoy.