4. It has a population density that​—with the exception of four other cities—​is twice as high as any other city in the world.

4. Hong Kong, with 248,000 people per square mile [96,000 per sq km], is followed by Lagos, Nigeria (143,000) [55,000]; Dacca, Bangladesh (138,000) [53,000]; Djakarta, Indonesia (130,000) [50,000]; and Bombay, India (127,000) [49,000].