In the stream
There is nothing at the posted coordinates!
Work out the sudoku to find the cache!
N51 F(B-F).(G+F)(E-A)B, W2 (D-E+F)E.G(D-B-G)(D-B-G)
Walk down the path to the stream until you see the little brick thing. Although the coords are out, it is now part of the puzzle.