Hitler's Island Madness (2012)

As soon as Hitler's forces occupied the Channel Islands in 1940 he ordered a series of fortifications to defend the only British territory he ever conquered. The problem was he never stopped - pouring men, concrete and weapons into the islands. By 1944 his officers talked of the Fuehrer's inselwahn - his 'island madness' and the Channel Islands had become the most fortified place on earth.

Unfortunately the movie Hitler's Island Madness is not yet available on HBO Max.