Having visited the English Heritage site of Tintagel Castle ruins in the spring of 2022 and nearly getting blown off the top of the headland I managed to visit again in the Autumn. I was lucky that the site was closed and I was able to do a short flight with my DJI min 3 drone over the site and even under the bridge. I think you wouldn't be able to do this during the day on any other day of the year other than maybe Christmas Day.