The cach is not at the given coordinates.
You will find the cach buy solving the puzzle.
Specialtools my be needed.
Bring Your own pensil
Good luck.
N: 51-81-5-62 81-12-51-6 41-5-22-5-91 5-41-51 51-32-02 5-41-9-41 5-22-9-6
E: 41-5-22-5-91 42-9-91 5-22-9-6 5-41-51 51-32-02 5-5-81-8-02 5-41-51