I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission requirements unknown.
https://www.english-heritage.org.uk/visit/places/thornton-abbey-and-gatehouse/
There is a car park in front of the gatehouse and a few fields around. The Abbey is to the East behind the gatehouse where you would have to try find somewhere to pull up and walk from. Its not the best of roads on that side but there are a few footpaths that would be OK for TOAL.
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 19/09/2021. It remains the responsibility of any pilot to check for any changes before flying at the same location.