Parc naturel régional Gruyère Pays-d'Enhaut - Just above the village of Grandvillard, the Tâna stream traverses layers of vertical limestone rock before falling dozens of meters. This spectacular waterfall continues to wear away at the rock, which sometimes causes rock slides. A portion of the Tâna’s water is caught and sent through turbines to produce electricity. During periods of high water levels, as in August 2005, the river can overflow its banks.
This area, with its small cave dedicated to Notre-Dame of Lourdes, converted in 1958, is also a pilgrimage site. Numerous visitors come here to pray in the fresh air.