Kowloon Walled City was a Chinese military fort in Kowloon, Hong Kong, which became an enclave after the New Territories were leased to Britain in 1898. Following Japanese occupation during World War II, the Walled City developed into an extremely dense, largely ungoverned urban settlement. From the 1950s through the 1970s, it was controlled by Triads and had high rates of prostitution, gambling, and drug use. In 1987, the Walled City contained 33,000 residents within its 6.5-acre (0.03 km2; 0.01 sq mi) borders.
In January 1987, the Hong Kong government announced plans to demolish the Walled City. After an arduous eviction process, demolition began in March 1993 and was completed in April 1994. Kowloon Walled City Park opened in December 1995 and occupies the area of the former Walled City. Some historical artifacts from the Walled City, including its yamen building and remnants of its South Gate, have been preserved there.