Along the national cycle route PC 20, between Kautenbach and Wiltz, there is a former state quarry near the village of Merkholtz. From 1910 to 1961, greywacke was extracted and processed into gravel for national road construction at this industrial site. Although the facility is no longer in operation, nature has reclaimed the space over time. Thanks to the industrial prior use, various species of plants and animals have established themselves in these man-made habitats, which would not have been possible otherwise. A part of the area has been designated as a Natura 2000 protected zone, highlighting its significance for nature conservation. The 'Former State Quarry Merkholtz' project aims to commemorate the industrial history in the Wiltz Valley and emphasize its connection to the present-day natural environment.