Nature

Les Grottes de Vallorbe. Photo Courtesy: Les Grottes de Vallorbe.

The Fairytale of the Vallorbe Caves

About 150 million years ago, a shallow sea covered the entire Jura region on the site of the current Vallorbe caves in the canton of Vaud. The complex geological history of the formation of the caves would take another 120 million years. About 7 million years ago, the sea withdrew from the region for good, when the African continent and the European continent collided and the mountain ranges of the Alps and the Jura came into being. The River Orbe has two springs. The source of the Orbe superior (Orbe supérieure) is the lake of Rousses (lac des Rousses) in France and flows into the lake of Joux (lac de Joux) in Switzerland and then goes underground. Besides, there is the parallel underground Orbe, the Orbe inferior (Orbe inférieure), that has rainwater and melted snow as a source. The two Orbes come together in the Caves of Vallorbe, and around two-thirds of the water consists of the Orbe inferior. However, Orbe is not the only river that flows underground. In the large and small Grotte aux Fées (la grande et la petite Grotte aux Fées) there are separate watercourses, with their source. The underwater lake in the Caves of Vallorbe is the network of the Orbe and other sources. Underwater lighting shows that this lake is quiet and almost stationary. An enormous gallery stretches out over 600 metres. This underground Cathedral (La cathédrale souterraine) and the Great Hall (La Grande Salle), with its imposing stalactites and fistuleuses, limestone, and numerous stalagmites, is the centre of the caves. The underground Orbe flows between enormous boulders and over millions of years has created the most beautiful works of art and galleries with stalactites, stalagmites, pillars, draperies, columns and fistuleuses. A magical underground fairytale world. The Trésor des Fées houses the mineral collection and shows the underground mineral wealth. (Source: G. Favre, Les Grottes de Vallorbe, Vallorbe).