In a disclaimer-like fashion, I'll like to point out that I'm going to list four of many un-worldly sized guns in this post, and that they are not in order depending on awesomeness. So don't start sending your hate mail if your favorite super-gun was unmentioned. (Although you should mention it below in the comments, we might just add it here.)
The Paris Gun - Germany
Named after the city it bombarded during World War 1, it's one of the largest guns you'll ever see. Although in Paris, they never saw it coming, literally.
Why would that be? How could the millions of people in Paris miss a gun that weighed 246 tons, 28 meters long, and was as tall as a skyscraper*? Maybe it's due to the fact that it was used to bombard cities at over 81 miles away? The Germans could sit around in beach houses full of women partying for hours before the people in Paris discover that the sky is not in fact falling.
