Where was The Phantom of the Opera (1916) filmed?
1916 film by Ernst Matray
The Phantom of the Opera (1916) was filmed in Weißensee, 1 place named in its German Wikipedia’s Produktionsnotizen section, in Germany. 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 German Wikipedia's Produktionsnotizen section
German Wikipedia’s Produktionsnotizen section names 1 place. Each links to the sentence that says so.