The views from this location are excellent and the Ridgeway path passes through here. After visiting the top of the hill then you will move down to a location where you can see the white horse.
More information about the White Horse can be found at Bill D's excellent web site.
The above co-ordinates will take you to an information plate. Take the LAST phone number on the information board as ABCDE FGHJKL (make sure it really is the last phone number) then the cache is at N51°2G.FGD', W01°DA.C(B-D)H'.
This cache is located a mile from the first location, some distance from the sensitive area. When replacing the cache please ensure it is hidden from view in every direction.
You can park safely adjacent to the offset clue and the final cache. However, please beware traffic by listening for approaching cars when rejoining the road. An Ordnance Survey map for the overall location is available at this web site.
Please check out the Geocaching Association of Great Britain offering support for Geocachers in GB.