***13.08.2007-09.30: Some smaller updates: description, hint, rating.***
You can park near the « Burrigplaatz » in North of Luxembourg, N50°09.691’ E006°01.422’.
Go in direction 63° for 455 meters. In front of the Hotel-Restaurant Knauf, follow the main road nortwards to pass around the hotel's property. So now it should be easy to find this big dark hole in the hill.
Following this darkness you have to count the “security holes “ on your right side.
A= __ __.
At the end of the darkness, on your right side, you will find a dug-out or “house”.
How many holes are inside?
Needful things: a lamp or torch, good shoes or rubber boots (ground could be wet).
The coords aren´t right anymore.
But this spoiler photo should help you.