SuperBeaverInc.
Groucho
Make it submersible. Really it wouldn't be any worse than any current city. At least it would have the ability to move around if under attack.
In the case of a world ending scenario it could even be built with space capable rockets to ensure the continued survival of the Human race.![]()
Or better yet, a flying aircraft carrier!

Washington DC because Canada and Mexico should become a part of the United States of America. Mexico was considering it a few years ago and several Canadian provinces have secession movements.
Only Quebec has a serious secessionist movement. Second most active would probably be Newfoundland, but its not really that large.