"There were many bunkers in the GDR, for the Stasi to save themselves in and repopulate the earth - if they remembered to take any women with them."

This film gives a tour of one such bunker, just north of Berlin. It was opened to the public for just three months in 2008 and has since been sealed with concrete. As the tour guide says, "you can really feel the danger and the fear from that time". More information is available here and, for a more in-depth tour, watch this DW-TV film: