From the last cache follow along the track for about twenty to thirty yards. You are looking for a path on the left which is not clearly marked. The path goes through the gates marked "Area patrolled by labradors" (I've checked this with the residents there and added a waypoint on the map....).
This cache is a traditional cache and is at the published co ordinates.
Having found this cache follow the path which goes straight across the field in front of you