I first heard about it on 99% invisible https://99percentinvisible.org/episode/episode-66-kowloon-walled-city/ https://99percentinvisible.org/episode/episode-66

I first heard about it on 99% invisible https://99percentinvisible.org/episode/episode-66-kowloon-walled-city/ https://99percentinvisible.org/episode/episode-66-kowloon-wa.... I recommend it if you have 15mins.