Berlin's Unterwelten

Narrow, dark, and cold. After much renovation work, Berlin has opened up its World War II network of bunkers ~ rail lines and bomb shelters that housed tens of thousands, especially during the torrential bombardment of the city toward the end of the war. A group called Berlin Underworlds Association takes visitors on a tour (video): http://news.bbc.co.uk/2/hi/programmes/fast_track/9457270.stm