I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission not required.
TOAL was from the public bridle way on the North side of the field above the long barrow. Note that the fields around the long barrow belong to a local farmer (which I met with).
Unlike, it's twin, West Kennet Long Barrow, there is very little known about this one. The local farmer informed me that East Kennet Long Barrow had collapsed long ago, and has not been excavated though there were some 19th century explorations. It is larger than West kennet, 106 metres x 50 metres, and there seems to be megaliths in the SE under the mound.
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 29/01/2022. It remains the responsibility of any pilot to check for any changes before flying at the same location.