Where was The Birch Wood filmed?
1970 film by Andrzej Wajda
The Birch Wood (1970) was filmed in Mińsk Mazowiecki and Kampinos Forest, 2 places named in its Polish Wikipedia’s Produkcja section, in Poland. Wikidata records no filming location for it at all, so the article is the only recorded source. Each place says where its claim comes from.
Places per Polish Wikipedia's Produkcja section
Polish Wikipedia’s Produkcja section names 2 places. Each links to the sentence that says so.

