The blueprint for a floating city has just been approved by the largest port construction and design company in China. It's entirely self-sustainable, and extends underwater.
If NYC were its own country, and the NYPD was its army, it would be the twentieth-best-funded army in the world, just behind Greece and just ahead of North Korea.
Rio de Janeiro was once capital of Portugal, making it the only European capital outside of Europe.
There is a city in New Mexico called Truth or Consequences.
In major cities like Brooklyn and London, there are fake townhouses that hide subterranean chimney vents, emergency subway exits, and more. Camouflaged in plain sight, they normally go unnoticed within their architectural surroundings.