Batman's been there, sort of. Jean-Claude Van Damme has walked its streets, if they can be called that. Special agent Jason Hudson from Call of Duty: Black Ops fought a running gun battle there, virtually speaking, and Ridley Scott (Blade Runner) concocted futuristic settings inspired by it, though it's been gone now for 20 years.
Lots of us have probably never heard of Kowloon Walled City, a maze-like slum that at one time was said to be the most densely populated place on the planet. But I'm totally geeking out over it. Big time.