I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission requirements unknown.
Arbury Hill in Northamptonshire is a distinctly shaped hill found 5½ miles south-west of Daventry. At 738 feet, Arbury Hill’s summit is the highest point in Northamptonshire.
The summit of Arbury Hill was one in a series of points used for triangulation in 1784 to determine the exact diameter and magnitude of the Earth, in a sequence of measurements undertaken by the British Government. There is a Triangulation station on the summit.
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 27/08/2021. It remains the responsibility of any pilot to check for any changes before flying at the same location.