In this area the Romans already used building stones out of limestone (marl). It is believed though that they used open air quarries for that purpose. In the early 15th century underground quarries were used to gain marl.

During the early 16th century most of the quarries we explored were built. After that the excavation slowed down and finally came to a full stop around 1850. After that the loose marl material was scratched of the walls and digged out of the floors, creating extra high hallways, to be used for agricultural purposes.


Since the late 1970's the whole area has been designated nature reservation. Before that the Belgium cement industry was planning on digging away the complete area. For a while it was closed down with walls but soon reopened by the 'underground' people. Currently there are rumours that it will be closed up again soon.



A big thanks to our guide Patrick Dinjens for showing us this place.