Impressive grotto and pilgrimage site. You should really stop here and enjoy the gentle coolness and fill your bottle with the water from the Karlsquelle (which is said to have healing powers).
These caves constitute a fascinating network of caves and cavities. You can visit the Truchet, Creux aux bêtes, Silberloch and Lucelle caves, which reveal the geological history of the region. These caves are a great place for photography!
The name is a bit off-putting. What I found, however, was a pretty little valley with a small stream flowing through it. The only thing reminiscent of a "cookie" is …