The Ardennes are also known as the Ardennes Forest or Forest of Ardennes. Low hills with extensive forests and rough terrain, extending over Belgium, Luxembourg, France and Germany. Geologically, the range is a western extension of the Eifel in Germany. Raised during the Givetian age of the Devonian (382 to 387 Ma), the former mountain ridge is eroded to its basement. This is called the Hercynian orogeny, which created other mountain ridges in central Europe, e.g. the Armorican Massif, the Massif Central, and the Vosges. It shows metamorphic rocks, shists and marble, intensive folding and tectonic movements.
The area is known for slate mining, the whole area in all four countries has numerous abandoned slate mines, and there are slate museums all over this area. The French slate mining sites are actually connected by the Route de l’Ardoise (Slate Route), five stops along a 440 km long route. There is only one stop on the Slate Route we have not listed, the village Haybes. This village is on the route because the houses are excessively built using the slate, but there is no quarry or mine.