Where was Les filmed?
1980 film by Vladimir Motyl
Les (1980) was filmed in Nikolo-Prozorovo and Nikolo-Prozorovo, 2 places named in its Wikipedia article, in Russia. 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 Wikipedia's article
The Wikipedia article names 2 places. Each links to the sentence that says so.

