Via overstate, one of the most fascinating places there ever was, and one of the chief inspirations for THE LEVELS:
Kowloon Walled City | A population density nightmare
Kowloon Walled City was a largely ungoverned Chinese settlement in Kowloon, Hong Kong, comprising of 350 interconnected high-rise buildings where 33,000 residents lived within a plot measuring just 210 meter by 120 meter. Originally a Chinese military fort, the Walled City became an enclave after the New Territories were leased to Britain in 1898. Its population increased dramatically following the Japanese occupation of Hong Kong during World War II and reached a peak of 33,000 residents in 1987. When it was demolished in 1993-94, it was thought to be the most densely populated place on earth.