Koppelberg

Greedy ones beware! The ‘auvelmenkes’ in the Koppelberg are not afraid to be mischievous... The Koppelberg is a motte hill (an artificial earth mound) on which a castle stood in the Middle Ages.
Just like with the Koppelberg, most motte castles have fallen, and only the hill slightly rises above the rest of the landscape as a reminder of centuries of history. A legend has been passed down about the ‘auvelmenkes’ who are said to live at the bottom of the motte hill.
They would come out at night to wander the village in groups. At night they would clean the pots and pans that mothers left outside in exchange for a large plate of rice pudding, generously sprinkled with brown sugar.
You get what you give: if you were stingy and didn’t leave any drink or food for them, you were at the mercy of their mischief... And you could certainly forget about that clean dishware.

Tourist Board South Limburg (Visit Zuid-Limburg)