Wolf’s Lair (Poland). 'The Wolf’s Lair, Hitler’s headquarters during WWII, was so well designed that the Allies had no idea it existed until it was overrun by the Red Army in 1945. They might not have needed to had one of Hitler’s own men, Colonel Claus von Stauff enberg, been more successful in his bid to assassinate the Führer here six months earlier. The ramshackle location takes a little imagination to appreciate fully.' http://www.lonelyplanet.com/poland
800mm super heavy rail gun Dora. Adolf Hitler (Center), Albert Speer (left) and other dignitaries arrived at the site at Rugenwalde (now Darłowo, Poland), where they were represented the 800 mm super heavy rail gun Dora (80-cm-Kanone (E) and the prototype of the SAU SD. Kfz.184 'Ferdinand'. Rugenwalde, March 19th, 1943.
Wolf's Lair, May 2012. Wolf's Lair is the standard English name for Wolfsschanze, Adolf Hitler's first World War II Eastern Front military headquarters, one of several Führerhauptquartier (Führer Headquarters).
Enigma Machine - Enigma Machine During World War II, the Germans used the Enigma, a cipher machine, to develop nearly unbreakable codes for sending messages. The Enigma's settings offered 150,000,000,000,000,000,000 possible solutions, yet the Allies were eventually able to crack its code. By end of the war, 10 percent of all German Enigma communications were decoded at Bletchley Park, in England, on the world’s first electromagnetic computers.