There is an interesting sandstone maze near Berdorf in Luxembourg, just few kilometers from German border.
This Jurassic (probably) sandstone formation is cut by numerous clefts that form an interconnected network of passageways. It is easy to get lost in this labyrinth of moss covered sandstone walls.
The sandstone is fine- to medium-grained, weakly cemented, and yellow in color.
I recommend to visit this place if you happen to go to Luxembourg and have some free time. The capital of this small country is very scenic as well but these rocks were definitely the most interesting thing I saw there.
The sandstone disintegrated into fine sand. The width of the view is 10 mm.