There is nothing at the posted coords but you can go there if you like but it wont help you find the cache.
This cache is a Bonus for the Amesbury Adventure Lab. You will be able to view the Bonus numbers in your Journal when completing each of the 5 locations. If you missed any Bonus details you can go back and view them in your Journal entries.
You will find the cache at N 51 09. ABC W001 46.DE1
A photo opportunity against an Amesbury Historic sign is available across the road.