The Champignon is a solitary boulder of Luxembourg sandstone in the shape of a mushroom. It is the weathering remnant of this sandstone layer, which originally extended further north here. A few metres to the south, it is still completely preserved. To the north, on the other hand, one can look far into the hilly marl landscape. This rock owes its shape to the different characteristics of individual sandstone layers: the top is formed by a solid sandstone layer, the base by layers that are easier to remove. Around the mushroom are other sandstone blocks that show special traces of human use, such as polishing grooves. These were formed in the Stone Age when people sharpened their stone tools on the sandstone. Due to the thin sand cover and the associated dryness, a rare habitat developed here: a sandy dry grassland with heather.
The mushroom is the geosite of the Year 2021.