During British rule, this city rested just outside of Hong Kong, China serving as a watchpost to protect pirates. It was then occupied by Japan during the second world war and then overrun by thousands of squatters following Japan's surrender.
However, neither China or Britain took responsibility so it became its own lawless city with its residents making their own modifications – labyrinthine corridors illuminated by fluorescent lights because the sun couldn't penetrate it – and using it for setting up brothels and opium dens. It was torn down 1993 to avoid further abuse.