You'll come to a spot, you never were
before!
Be sure to wear good hiking shoes, a rope and a torch could also be
usefull.
Although the given coordinates are not very accurate, the target
cannot be overlooked!
When the construction of the dam in Esch-sur-Sûre was finished and
the reservoir was filled for the first time in 1959-1960, some of
the old roads and bridges connecting the villages around the Sûre
were flooded. For this reason, some years before a new road was
built between Riesenhof and Esch-sur-Sûre. For the realization of
this road the construction of 2 huge bridges were necessary: the
first one relying Insenborn to Lultzhausen ("Lëlzer Bréck") and
crossing the Ningserbaach, the second one ("2. Bréck") crossing the
Dirbech. From the bridges you have scenic views on the upper-Sûre
lake... but to find the cache, you'll have to search some meters
deeper ;-)
You can find more information in luxembourg language at Wikipedia
Va gur sbhaqngvba, jrfgrea punzore.