Where was Le Masque de fer filmed?

1962 film by Henri Decoin

Le Masque de fer (1962) was filmed in French Riviera, Sospel, Château de Maisons, île Sainte-Marguerite, Château d'Écouen, Château de Courances and 4 more places, 10 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.

See them on the map → Wikipedia Source data