Mostyn and I undertook this strenuous walk today, not a great distance but a lot of stiff climbing reaching the high point of Mont Agut (1020 meters). Le Devois is the head of the valley for the stream that runs through Graissessac, le Ruisseau de Provères. Graissessac was once a very busy mining town, you can see some terracing from the mining at the top left of the photo. This part of Hérault was very rich in coal and other minerals, including zinc, copper, manganese etc. Coal mining at Graissessac lasted from the 18th century until the 1960s.