In the wooded region of Belgium between Köpfchen and Lichtenbusch, you find the source of the river Gueule. Very quickly, the smallest tributaries change the stream into a little river winding its way across the Pays d’Eupen, the Pays de Herve and the « Heuvelland » (hilly countryside).
The valley of the Gueule has 53 kilometres of walks from the source of the river to where it joins the Meuse, passing by La Calamine, Plombières, Valkenburg … The route is marked by signs with vertical stripes of Blue-white-blue.
The geological variety along the way explains the diversity of habitats
and species present in the Gueule valley. Therefore it has been included
in the Réseau Natura 2000 (European ecological network).
In the Gueule valley, the ridges are generally covered by forests (beech and oak). Amongst these, there are the woods of Preuss, Schimperbos, Beusdael and Hees.
The Plombières mine site contains a natural reserve characterised by the presence of the calamine grasslands.