Kowloon Walled City was an enclave in the outskirts of Hong Kong. It was originally erected as a Chinese military fort. Under British rule, people lived and worked there without government administration or law enforcement. After World War II, the population soared with refugees, and buildings were built between buildings, up to 14 stories tall. At its height, the city had 35,000 residents, or 1.3 per square meter, making it the most densely populated spot in the world! Kowloon Walled City was demolished in 1993-94, and is now a park.
A Japanese research team documented the construction of Kowloon Walled City shortly before demolition, after residents were evicted. They constructed an architectural cross-section of the buildings, illustrated as if people were still living there. It was published in a 1997 book. Belarius has a copy of the book, and scanned and digitized the cross-section for posterity. Click on the image here to enlarge, and see the many apartments with people living their everyday lives.
You'll also see factories, shops, classrooms, entertainment venues, laundries, offices, tea rooms, brothels, medical clinics, shipping centers, gambling dens, and martial arts studios. On the roofs you'll find gardens, playgrounds, clotheslines, and an array of antennas. There are plenty of cats and dogs, and if you look closely, you'll find one guy about to be shot. Details highlight constant construction and renovation, and waste disposal problems. This could be a serious time sink. -via Metafilter
(Top image credit: Ian Lambot)