The Wolf's Lair. The Wolf Johnson.

Heavily fortified. Heavily on meth. That would actually make a lot of sense because he was increasingly paranoid. So there was on this July 20th plot, they wanted Himmler and a gearing, if not Goebbels too, in the room with Hitler. But as many times as they tried to do this, Himmler was nowhere around Hitler at this time. Which is evidence that Himmler knew something was up and wasn't about to be in the same room as Hitler at any point.