WWII movie from the 50-60, main ch. works inside underground facility.

Tools    





Hi!

I'm trying to find a movie that is like "The Guns of Navarone" or "The heroes of Telemark": theme, date, importance, quality of the cast, etc. It's a WWII movie where the main character (and some other allied friends?) poses as a scientist to work in a secret, very well guarded, nazi underground facility. This underground facility is massive in size and it's inside a mountain; the walls are visibly made of rocks. There are also makeshift beds, or bunks, where the people working there sleep. All the workers must pass a security check before entering. The main character, the one posing as a scientist, is probably trying to blow the whole thing up or maybe he is a spy...

Thank you!