[necro]

Building code FAIL:

Square buildings folded up into one another as thousands of modifications were made, virtually none by architects or engineers, until hundreds of square metres were simply a kind of patchwork monolith

The Kowloon Walled City was also infamous for its high number of unsanitary dentist clinics, since this was where unlicensed dentists could operate without prosecution.

It had 50,000 inhabitants on 0.026 km²

It was so intertwined it took mail carriers 6 months to learn thier route. It was demolished in 1994.