Gold Mine of Chefna

The end of the last century was a golden age on the edge of the Ambleve. Some adventurers use the gold pan and sluice, or scour the sand and gravel of the river like American prospectors do.
The so-called gold-bearing region extends from Faymonville (country of Malmedy) to the Plateau des Tailles (near Baraque de Fraiture). Small artificial mounds (between 1m and 5m high) testify to this along the river Chefna creek.
Source: "Vallon de la Chefna" information board at the rest area

In this small valley the search for gold nuggets took place in pre-Roman times and then from the 19th to the beginning of the 20th century.
Source: refuges.info/point/7947/cabane-non-gardee/Ardennes-Eifel-Hunsrck/Cabane-de-l-Orpailleur

If you look closely you can see where the stones were broken in search of gold.