From the earliest bunkers of WWI through the ultra-futuristic ones of
tomorrow's wars, we trace the story of defensive fortifications. In the
constant struggle to hold off ever more potent forms of attack, bunkers
function in a variety of forms. Three mammoth block structures comprise a
submarine bunker at Lorient, France, able to house 20 subs. We visit
Churchill's Cabinet War Room and Hitler's Berlin bunker, as well as
backyard Cold War bunkers and those that protect nuclear weapons
themselves.