The true cache location can be obtained by solving the following
puzzle.
You can assume North 50 and West 001 but the puzzle will give you
the remainder of the figures.
A4Q8A 4Q5Q6 A2Q8Z 2Z1Q3 Q4Q9A 4Q9Q7 Q4A2Q 3Z4Q3 Z6Z6Q
9Q7A5 A6Q5Q 5A6Q4 Q3Q3Z 6Q8Z6 Q3Q5A 6Q4Q3 Q3Z6Q 8Z6Q3
A correct solution of the puzzle will give a checksum (all 15
digits) of 52