In the soil of the Hautes Fagnes were enormous lens-shaped ice cones, with the tip of the cone going downwards. When these ice cones had eventually molten, they had created little craters that were gradually filled up with mosses. However, until today one can still clearly see the outlines of these ice-age scars. The dam was constructed in 1951 and creates a lake of 125 hectares at the confluence of the rivers Vesder and Getz. The artificially created lake supplies the water for the area of Eupen and greater Li ge.
Visitors can park their car nearby and walk over the dam.
Sail boats are allowed on the lake, but motor boats are banned in order to keep the water as pure and clear as possible. There is a view tower and also a little artificial hill with an altitude of 6 m. If you climb the staircase on the hill you will be at an altitude of exactly 700 m above sea level.