Where was The Prayer filmed?
2018 film by Cédric Kahn
The Prayer (2018) was filmed in Mens, Tréminis, Saint-Baudille-et-Pipet and Châteauneuf, 4 places named in its Wikipedia article, in France. 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 4 places. Each links to the sentence that says so.