We head west through the village and then follow the course of the Eisch river downstream, which marks the border with Belgium in this area. Shortly before Eischen, we turn around, cross the river and hike back along the Eisch valley. At the former Steinfort dam, we enter the forest towards the Hafferbësch and from there return to the starting point.

The “Schwaarzenhaff” nature reserve is part of the Natura 2000 zone “Valley of the Mamer and the Eisch”; its area of 6,797.60 ha makes it the largest protection zone of European interest in Luxembourg. The site includes two zones requiring special protection: the “Steekollen” near Steinfort and the “Jongebësch” quarries near Eischen. The nature reserve includes various types of habitats, such as semi-natural dry grasslands, an alluvial forest, wet meadows, and beech woods. It is also a habitat for very rare species such as alytes obstetricans (common midwife toad) and bats.