I knew there were some restrictions on certain castles in Germany. I looked into it and could not find any restrictions on Schloss Wernigerode. However, to not fly over people, I flew shortly after sunrise and well before the castle opened. The main reason I flew over the castle was to set the center of the POI for the rotational flying. I might look into other ways of POI center, then I could get awesome video with staying 100+ feet from the building.
I also flew along the Amalfi coast and Tuscany in Italy. Again, I made the effort to not fly over people. I read the drone rules for each country I visit & carry a copy with me in English and the native language. I haven't been questioned on my flying, but I do avoid trying to attract attention.