A string of fortifications (named after French minister of war André Maginot) erected along the French-German frontier prior to World War II that were completely outflanked by Hitler’s armored blitzkrieg through France and the Low Countries in the summer of 1940. During the winter of 1967–1968, Bond producer Harry Saltzman and production designer Syd Cain toured the line, searching for a possible redoubt for Ernst Stavro Blofeld in On Her Majesty’s Secret Service.
Accompanied by a group of French officials, they were given a complete tour of a key position southeast of Metz. Saltzman and Cain trudged along miles of concrete tunnels, viewing the facilities that were designed to support a huge French army in static defense. After five and a half hours of walking among huge gun emplacements, underground airfields, and railroads, Saltzman turned to Cain and asked, “What do you think?” Replied Cain, “I think we can build all of this in the studio.”
In the end, Eon Productions was spared that chore when the unit discovered Piz Gloria, the marvelous mountaintop restaurant above Mürren, Switzerland, that eventually became the stronghold (and allergy research center) of Blofeld (Telly Savalas) in the film.
 Syd Cain, interview by Steven Jay Rubin, London, June 18, 1977.