In 1933, Heinrich Himmler signed a 100-year lease for Wewelsburg castle in Büren, Germany. The space became a clandestine training space for the SS.

Built in 1934, Ordensburg Vogelsang, a virtual Nazi Castle, was constructed to build the New German elite future leaders of the Reich.

When the Nazis took Ksiaz Castle, it wasn't for the view. Secret staircases and lifts were built, while underneath, a vast network of tunnels was taking form.

Outside the town of Pölitz lie the ruins of what was once one of Germany's most important assets - a place that kept the German war machine moving.

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.

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.

Germany's preparations for WW2 began years before 1939. Under various guises, Germany began work on what would become their most technologically advanced front.

Guided missiles, the Wasserfall, and the war-changing V2 were dreamed up and tested in Peenemunde, a German seaside city suddenly overtaken by Nazi elite. Along the Baltic coast, scientists like Wernher von Braun, designed and tested weapons to bring the Allies to their knees.