The Fluweelengrot was probably created in the 11th or 12th century. During the months when there is no Christmas market, you can take a guided tour.
Marl was mined from the quarries by block breakers to be used as building stone. The result of this marl extraction is an extensive labyrinth of old and winding passages.
The Fluweelengrot houses a treasure trove of impressive murals, inscriptions, sculptures, and a chapel dating from the 18th century.
During World War II, when the Germans were occupying the area, the cave served as a shelter for the people of Valkenburg and American soldiers.
The temperature in the Fluweelengrot is 12 degrees Celsius in both summer and winter.
