The Montagnes Noires (French, 'black mountains'), also known as the Montagne Noire (French, 'black mountain')[1] and in Breton as Menez Du[2] are an east–west oriented range of hills in Brittany centred on the town of Gourin. They culminate in the peak of Roc de Toullaeron (Breton: Roc'h Toull-al-Laeron)which attains a height of either 318m[3] or 326m.[4] Other significant peaks include Ar Menez (304m) and Montagne Noir (307m) (or, in Breton: Menez Du).[5]They are composed from a range of Precambrian, Ordovician, Silurian and Devonian rocks forming a part of the Variscan orogen and include sandstones, quartzites and slates.[6]
The hills form a part of the border between the départements of Finistère and Morbihan and just extend into Côtes-du-Nord.
References
48°09′N 3°40′W / 48.150°N 3.667°W