Lac de Moron, reservoir on the border between France and Switzerland

Lac de Moron is a reservoir in the Jura massif on the border between Switzerland and France, formed by the Châtelot arch dam on the Doubs. Its elongated body of opaque green water begins at the Saut du Doubs, a 27-metre waterfall, and lies at 716 m above sea level, with steep forested slopes and pale rock bands descending to the shore.

The dam was completed in 1953 using an arch design where the curved structure holds back water through its shape. This construction made it possible to use the Doubs river for water storage and power generation.

The name Moron comes from the hamlet of Moron on the Swiss bank, in the commune of Les Planchettes. The lake lies between Villers-le-Lac in the French Doubs department and Les Planchettes and Les Brenets in the canton of Neuchâtel. The Châtelot dam and the upkeep of the banks are managed by the Société des forces motrices du Châtelot.

The reservoir is accessible only on foot as there are no vehicle roads, but walking trails are well-maintained and lead from nearby villages to the lake. The best time to visit is during warmer months when paths are dry and the area is more accessible.

From the dam, visitors can observe water at different heights on each side, revealing the force of this structure. The construction from the 1950s shows engineering work from an earlier era.