Haut Martelange lies near the French frontier on the western border of Luxembourg. The museum occupies the premises of a former slate-working enterprise comprising 22 buildings across an 8 ha site. It was conserved by the government of Luxembourg from 2003 after agitation by les Amies d’Ardoise since 1993. Visitors are taken on guided tours through underground galleries and can explore on the surface the sheds where blocks of slate were sawn and split, and the blacksmiths’ shop where tools were made and maintained. They can also see the owner’s villa, set in a park in the English style, and the humbler dwellings occupied by the workers. Transport around the site is provided by a narrow gauge train.
The Musée de l’Ardoise is linked through the organisation Le Réseau Ardoise d’Ardenne and the trail guide La Route d’Ardoise with similar slate museums at Alle-sur-Semois and Bertrix in Belgium and Rimogne in France.