Dora Gun was manufactured by the German company Krupp for the third Reich during World War II. Hitler had wanted a gun "able to pierce a meter of steel, seven meters of concrete, or thirty meters of dense earth": Link - Thanks Sammy and gahsoon!
Well , dont know about anyone else but I'm still hugely disappointed that there is no such thing as a giant robotic russian gun patrolling its borders. curse you photoshop for your oh so realistic imaging trickery!!!
random factory