Guided missiles, the Wasserfall, and the war-changing V2 were dreamed up and tested in Peenemunde, a German seaside village suddenly taken over by Nazi rocket scientists.
Germany's preparations for WW2 began years before 1939. Under various guises, Germany began work on what would become their most technologically advanced front.
In Poland lies a forgotten Nazi complex which could have sheltered up to 27,244 people from Allied bombs, the purpose of which largely remains a mystery.
Hidden in a remote mountainous forest is a structure nicknamed the Fly Trap or Hitler's Stonehenge. Researchers still have no definitive idea what it is.
Built in 1934, Ordensburg Vogelsang, a virtual Nazi Castle was constructed with the intention of building the New German; elite future leaders of the Reich.