It has lain hidden for nearly 70 years and looks, to the untrained eye, like a building site. But this insignificant tunnel opening in the soft sand of western Poland represents one of the greatest examples of British wartime heroism. And the sensational story became the Hollywood classic, The Great Escape, starring Steve McQueen.

Frank Stone, seated, with Dr Tony Pollard on the site of George
Who was the man who tapped his pipe on the hut wall to warn the diggers