Where was Breakout (1975) filmed?

1975 action film directed by Tom Gries

Breakout (1975) was filmed in Le Perthus and Fort de Bellegarde, 2 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