Eighty years ago in one of the most ingenious and audacious acts of defiance of World War II, 76 prisoners of war tunneled out of a German POW camp into a snowy forest. Few managed to make such bold dashes to freedom during the war, but an exhibit that opened Friday at the U.K. National Archives in London uses the 80th anniversary of the breakout as an entry point to explore escapes of all types — some physical, others creative — to ease the tedium and torment of captivity among prisoners of war and civilians held in internment camps in Europe and Asia.