The National Geographic documentary Stauffenberg: Operation Valkyrie tells the story of Claus von Stauffenberg and the attempt to kill Adolf Hitler on 20 July 1944.
A number of plots were hatched to assassinate Hitler but Operation Valkyrie, in which a bomb was planted during a meeting at the Wolf’s Lair (Wolfsschanze), came closest to succeeding.
For anyone interested in learning more about Operation Valkyrie I would recommend a visit to the German Resistance Memorial Centre, which is housed in the Bendlerblock in Berlin. Unfortunately, only a few of the exhibits have descriptions in English but a free audio guide is available. The displays on Claus von Stauffenberg are in his former office and a plaque in the courtyard marks the spot where he and his co-conspirators were murdered by a firing squad.
Stauffenberg – Operation Valkyrie

