You just need to go to the location above and collect the following information:
Look at the cycling signpost:
S = the total distance to everywhere except North Bretton.
(Also, each sign is double-sided, but only use each place once!)
Now walk under the footbridge. You can see a sign with a capital E at the top and some numbers below, like this:
E
???
##
Work out ??? minus ## and make this = PQ (a 2 digit number)
Also, you can see a 2 digit number alone on a square sign on the left side of the bridge arch. Call the second digit R.
Now, go and find the cache at: N52 35.PQR W000 16.0RS.