The Kowloon Walled City in Hong Kong was built gradually—building on top of building—over time. Without a single architect, the ungoverned and most densely populated district became a haven for drugs, crime and prostitution until it was demolished in 1993. Photo documentation of the site exists but for the most part much of the inner-workings of the city remained a mystery.
Perhaps due to its proximity, Japan, in particular, developed a keen interest towards Kowloon. Its demolition in 1993 was broadcast on national television. But watching the footage, what most spectators didn’t realize was that up until the night before demolition a team of Japanese researchers were taking precise measurements and documenting the vacated city. Their findings were compiled into a book that, among other things, featured this panoramic cross section of the city depicting what life was like inside. You can read more about the book on Spoon & Tamago, and if you look hard enough, a few rare copies of it are available online.