Not to be confused with Montagne Noire of Languedoc-Rousillon.
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 Variscanorogen and include sandstones, quartzites and slates.[6]