Until the beginning of the 20th century, tunnels were blasted here to mine the white feldspar-containing quartz porphyry, which was used to make porcelain. Remains of the extracted rock can still be found in front of the tunnel.
The mine tunnel is located just a few meters off the main path, a worthwhile detour via a side path. The tunnel was in operation from 1753 to 1905. Coal was mainly mined in the Hagenbach area.