...for many climbs around its riverbed.

The route starts in Gulpen (near the Mosaqua swimming pool, where there is plenty of parking available) and goes counterclockwise.
The route is almost entirely concentrated around the valley of the Gulp. The Gulp is a small river that springs in Belgium in the Land of Herve, flows into the Netherlands via the Voer region, and empties into the river Geul just north of Gulpen. The route follows the river Gulp first upstream (so into Belgium), and on the way back downstream.

This means climbs on the west side of the Gulp valley on the way there. Upon arriving in the Voer region, there is a short detour to the valley of the stream Veurs.
Ultimately, the route goes quite deep into the Land of Herve: rolling hilly landscape, with many meadows bordered by hedges, and the route crosses right through the center of the town Aubel.
On the route in the Land of Herve, there is a fairly steep climb (Mount La Clouse), carved out by the river Berwijn (La Berwinne). After this tough climb, you will reach the ridge located east of Aubel with magnificent views. Near Hombourg, after a descent into the Gulp valley, you need to turn left immediately at the lowest point (be careful at this turn!) and then follow the paved cycling path along a former railway line around Hombourg (you will need to endure about a hundred meters of cobblestone road to get onto the cycling path).

Via Sippenaeken and the climb of Kasteelstraat, you will find yourself in the Voer region again, in the village of Teuven, and eventually, you will cycle back into the Netherlands via the beautiful climb of Gieveld. You will then ride on the plateau south of Gulpen (Plateau van Crapoel) that gradually descends northward, and descend the Gulperberg towards the center of Gulpen. But it's not over yet, as you will finally climb the Beversberg. However, if you're tired of it, you can skip the Beversberg; after all, you are already in Gulpen: it saves you 6 km and 80 meters of elevation. 

There is a total of about 4 kilometers of (dedicated) cycling path on the route: along the ridge of the Oude Luikerweg between Reijmerstok and Euverem, and over the former railway line around Hombourg.

The list of climbs on this route:
Reijmerstokkerdorpstraat: a runner of a climb, long (3.5 km) but at most 4%.
Hoogcruts or Piemert (note: you then descend the steep and narrow Schilberg!)
Nurop: gradual climb on a car-free road
Magnebos: a longer climb that gradually becomes steeper and ends in a dark beech forest. 
Smidt-Neubau-Mabrouck: one climb in 3 stages (hence the triple name), but sometimes simply referred to as Mabroek.
Berg La Clouse (Kosenberg): the sting is in the tail!
Rue de Beusdael: with the Beusdael castle at its foot.
Kloosterhofstraat: 2 km of climbing with a nearly constant gradient of 4%.
't Gieveld: a magnificent climb through wooded area
Beversberg: a hidden gem of a climb.