I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission requirements unknown.
Parking is available right outside the Abbey - being church grounds they are open to the public with no specific restrictions but take it as you find it. Sunrise/sunset is always quieter and here is another spot to take off /land for shots of Margam House and park.
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 12/07/2019. It remains the responsibility of any pilot to check for any changes before flying at the same location.