Fall 2021 update: The passage through the lost valley is permanently closed in order to protect nature. Unfortunate but understandable. The route now has two trips to the Ternaaien-Boven quarry and the Ternaaien-Beneden quarry between which lies the lost valley. These are beautiful places for a pic-and especially at the last one we have a view of the valley closed.

Note! This walk is not a standard walk. You are in a dangerous environment with caves, rocks, precipices and there are some steep climbs in the walk. This is a journey of discovery as there is a lot to see here! Make sure you have good shoes and can walk. Do not walk in wet and wet weather. Stay on the trails. Sometimes you walk along an abyss! Be warned and be careful with children.

This difficult journey of discovery on the Caestert plateau sometimes passes through a real jungle and various caves of Marn. We walk this walk a few times a year, in different seasons. There is a great climb in the promenade, short but quite steep (after 1.3km). If you don't dare, go back to Groeve Caestert and take the wide path that winds until you get back on the road.

Near the starting point on Rue L'Illal is a nice car park.

This discovery tour connects all the highlights of this fantastic region:

250m Historic entrance gate
400m Old cellars under Caestert Castle
600m Caestert Quarry
700m viewpoint on the Meuse and the border post
850m Feij Quarry
1.0 km Former ENCI ammunition storage facility
1.3km View of ENCI factories
1.3km Steepest climb (go back if it is too steep)
2.0km Well with connection to Caestert quarry
2.4km Hoeve Caestert
2.5km Dolines on the Caestert plateau
2.6km Ternaaien-Boven quarry (from Aardappelenberg)
View 3.3km from Albert Canal and Kanne
3.8km Viewpoint on Albert Canal
4.1km Challenging hiking trail
4.8km Quarry Ternaaien-Beneden (Le Collinet)
4.8km View of the Lost Valley

Here is a nice blog of "Road trips with Kids".