Starting from the Tourist Office of Gourin, this itinerary will take you to the ridges of the Black Mountains through the place called Roc'h an Ankou, from where you will enjoy a magnificent panorama. You will evolve on an alternation of paths and trails on a hilly route that will also lead you to discover the Castle of Tronjoly, the peaks of the Black Mountains and the old slate quarry of Penquerhoët which was exploited in the early twentieth century.