At the given co-ordinates there is a bench with a commemoration carved into the top rail, it starts with a date of six numbers in the format AB/CD/EF. At the time of placing there was a couple sitting on the bench, enjoying the evening sunshine, if there are further numbers on the rail they are not relevant!
The cache is at the following location, you will need your algebra head for this one. The final cache is located about a mile away.
Congratulations to JOESMILE for first to find.
The cache is at N 50 3(D-B).((D+E)/2)(F-C)(E/A) W004 5(A2).(A+B)(A2+B)(E-F)