Fort Drum: America's Unsinkable 'Concrete Battleship'

Fort Drum, originally known as El Fraile Island, is a huge, now ruinous complex of concrete and steel that once guarded the southern entrance to Manila bay. It's construction and took years and for much of it's history, it was regarded as strange, unique oddity on the horizon of manila bay. For a brief few months amid the desperate defense of the Philippines during WWII, it proved to be a formable and impervious foe.