The cache is not at the posted coordinates and there is no point in going to them. To find out where it is hidden, solve the following puzzle.
I know this is not everyone's forte, but I happen to be a great fan of mathematics. To me, a number puzzle is a challenge that I enjoy, although the one below, perplexed me for a while, till I found the right formula. Mind you, non-mathematicians have sometimes solved this quicker than those blessed with arithmatic prowess, so please don't shy away from having a go.
So, there are two numbers you need to find. The first one is a funny one really and only consists of 3 characters and the second character is A. The third character minus the first character will give you B.
The second number was once used as a number before more modern (and more sophisticated) numbers were discovered. Nowadays it is more often used in a recreational context. Although it could be written with five characters it is more conventionally written with six. The fourth character of this number is C. The sixth character minus the third will give you D, whilst the third character of this second number should equate to E.
You should now be able to calculate the final coordinates of the cache which is hidden at:
N51 1C.E(A+B)B E001 1C.(E-C)D(C-B)
NB - Credit due to Mr Cryptic for the inspiration