I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission requirements unknown.
Cadwell Park Racing Circuit near Louth in Lincolnshire
https://www.cadwellpark.co.uk/
They don't allow drone onsite but being in the middle of nowhere there are plenty of fields around the place to start off from. Normally quiet but on some bike race days the place can be packed.
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 28/08/2021. It remains the responsibility of any pilot to check for any changes before flying at the same location.