"We're several dozen feet beneath Berlin, in a low-ceilinged concrete lair. The walls are marked with phosphorescent arrows, still glowing after more than 60 years, that point the way through heavy, gas-tight steel doors to other rooms in this warren of underground bunkers. "This was where the residents of a working-class Berlin neighborhood sought refuge during the air raids of 1945. The floors are strewn with rusty ammunition, guns, old boots, helmets, rations, military cots - items that offer vivid testament to wartime Berlin. Here it's easy to imagine the bombs thudding overhead, the city erupting in flames, families huddled together, praying for safety. Suddenly the stories that old Berliners tell about traumatic experiences during the allied air raids of World War II come to life. "To find the real Berlin you have to go underground," says Dietmar Arnold, "beneath the city's slick and modern streets, into the city's unconscious, as it were, history's hidden lair." History lives on in Berlin's underground bunkers Berlin Underworlds: http://berliner-unterwelten.de/