Secret Nazi Ruins (2019)

S1E6 Hitler's Invisible City

While the Soviet Army advances through Poland, they stumble upon a vast, concealed urban area spanning ten square miles, comprising over a thousand structures that the Allies were unaware of. Experts utilize cutting-edge scientific methods to uncover the secrets behind Hitler's ability to keep this ominous site hidden for years. The D.A.G. Fabrik Bromberg, a clandestine German explosives factory nestled within the Bydgoszcz Forest, was responsible for producing a significant portion of the munitions supplied to the Eastern Front.