Source du Pontet

Source du Pontet is a striking karst spring tucked into the Loue river valley, in the commune of Mouthier-Haute-Pierre in the Doubs department, in the Bourgogne-Franche-Comté region of eastern France. Combining a rare geological feature with the dramatic limestone scenery of the French Jura, it ranks among the most rewarding stops on the hiking trails that wind through the nearby Gorges de Nouailles.

What exactly is Source du Pontet?

Source du Pontet is a karst resurgence — a point where underground water re-emerges at the surface through a cave system carved into the Jura's limestone bedrock. The entrance opens as a large rock portal, formed long ago when a section of the cliff face collapsed. Inside, at the back of a chamber roughly a dozen metres wide, a small waterfall cascades over tufa (calcareous sinter) deposits built up as calcium carbonate carried by the water settles out of solution over time. The cave can be explored on foot for several dozen metres before the passage becomes more technical, which makes it a point of interest for cavers, though venturing deeper requires proper caving equipment and experience.

The water feeding Source du Pontet is connected to the nearby Grotte des Faux-Monnayeurs (Counterfeiters' Cave), located slightly higher up the same valley, before the spring's waters join the River Loue.

How do you get to Source du Pontet?

Two main routes lead to the spring. The shorter and easier option starts at the end of the chemin des moulins (the millers' path) in Mouthier-Haute-Pierre, passing the Syratus waterfall and the Grotte des Faux-Monnayeurs along the way before reaching the source itself — around 1.3 km one way. The second option is a longer and more demanding route starting from the source of the Loue and following the dramatic, and at points precarious, Gorges de Nouailles.

Hikers looking for a fuller day out often follow a loop trail linking several sights at once — the source of the Loue, the Grotte des Faux-Monnayeurs, and Source du Pontet — covering roughly 10.6 km and taking in the valley's main natural landmarks in a single outing.

What else is worth seeing along the way?

The path to Source du Pontet runs through one of the most scenic stretches of the Loue valley, known for its limestone cliffs, dense forest cover, and abundance of karst features. Along the route, walkers pass the Syratus waterfall and the entrance to the Grotte des Faux-Monnayeurs, whose name recalls a local legend about counterfeiters said to have once hidden coins there. The surrounding area is part of what is often called the land of Franche-Comté's springs, where karst resurgences, caves, and waterfalls form a dense network of natural attractions popular with hikers and nature enthusiasts alike.

Frequently asked questions

Is Source du Pontet suitable for families with children? The shorter route from the chemin des moulins is relatively easy and works well for most visitors, including families, though care is needed near the cave entrance and on damp sections of the path.

Can you go inside the cave? The first chamber is accessible on foot, but exploring further into the underground system requires proper caving equipment and experience — this is not a conventional sightseeing route beyond the entrance area.

What is the best time of year to visit? Karst springs like this one look their most impressive in spring and autumn, when water levels are higher and the waterfall inside the cave is more abundant. In summer the trail is easier to access, though water flow tends to be lower.

How do you get to Mouthier-Haute-Pierre? The village sits in the Loue valley in the Doubs department and is well connected by local roads to other towns in Bourgogne-Franche-Comté, from where most of the hiking trails toward the spring begin.

Are there other nearby attractions worth visiting? Yes — the immediate surroundings include the Gorges de Nouailles, the source of the River Loue, and Mouthier-Haute-Pierre itself, a village known for its traditional Comtois architecture and valley views.