Kowloon Walled City Park sits on the very site of the former Kowloon Walled City, remembered today as a haven of crime and debauchery. 
The site occupies a strategic point along the Kowloon peninsula and has been used by Chinese imperial officials since the 16th century. In 1841, when Hong Kong Island was ceded to Britain, Kowloon Walled City was already a garrison and was reinforced by the Chinese Government. The fort’s fate changed in 1898 when the New Territories were leased to Britain for 99 years. Although the walled city remained Chinese territory by treaty, the following year their troops and officials were forced to vacate. Behind them they left a power vacuum that was filled by criminals, and the garrison became a city within a city.  
Throughout the 20th century, fugitives and other criminal elements flocked to the lawless enclave. Beyond the reach of the law, the area mushroomed into a squalid maze of illegally constructed buildings, where everything from drug trafficking and prostitution to unlicensed dentistry flourished in a labyrinth of dank, dark alleyways.