This is one of many beautiful areas in Belgium worth spending a day hiking in..

The route of this 16 km (10 miles) hike follows the white signposts marked with a small green rectangle. We won’t be wasting your time with complicated calculations and projections, so you can focus on the beauty of the landscape.

This is one of the oldest dams in Europe. It is kept in place by its weight, and controls the flow of the water masses. It was built between 1869 and 1878; it was heightened in 1971, and the reservoir behind it has a capacity of 25 million m2 (900 cubic foot) of water. In the middle of the dam stands the statue of a lion, 13.5 meter (45 foot) tall, built by Félix Bourré. An observation tower allows for great views of the area, in particular of the Herzogenwald.

We will park the car at the big parking lot on top given coordinates.

WP01:

At this place, you will find an information sign, which will tell you the length of this route. It also shows features a trail map.
The 3 digits (not including the comma) = A

At the nearby tower you can take the elevator down and start your route by walking counter-clockwise around the lake.
Go to N50 35.(002 + A) E005 58.(793 - A), and proceed along the trail.

You will find an object at N50 34.(738 + A) E005 58.(275 + A). Count the number of wooden planks you walk over. This number will be B.

Now proceed to N50 34.(839 + B) E 005 58.(876 + B). On the left, you will find a tree with a brown sign with a number on it. We will call this number C.

We proceed to N50 34.(699 - C) E005.58.(501 + C) via a slightly less-maintained trail. At these coordinates, we find an object. What is it?
Is it a building? Then D = 100
Is it a bridge? Then D = 200
Is it a bench? Then D = 300

Walk via N50 34.704 E005 59.438 to a small shelter, at N50 34.(570 - D) E006 00.(136 + D) Count the vertical piles here, that support the roof. That number shall be E.
We are about halfway now. This may be a good point for a rest stop.

When we continue, we walk to N50.34.(833 + E) E006 00.(540 -E). What is the number of wooden elements one can sit on? Let’s call it F.

Keep going until you get to N50 35.(231 + F) E005 59.(387 - F). What have we got here?
If it’s a lamp post, G = 100
If it’s a feeding trough, G = 200
If it’s a great view, G = 300

Getting tired yet? Then let’s proceed to the penultimate point, at N50 35.(66 + G) E005 58.(677 + G). Here we find some train tracks. Could this have been an underwater train? Here you’ll find a date. The last two digits of the year are H.

Let’s do a checksum of the numbers now. Adding them up should be 877. If that’s correct, you may now proceed to the final coordinates.

The stash we will find on N50 35.(E + F + G + H + 23) E005 59.0(H - 10).

 :-)