The Kowloon Walled City was a densely populated enclave of China within the boundaries of Kowloon City in Hong Kong. Built as an Imperial Chinese military fort, the walled city became a de jure enclave after the New Territories were leased to the United Kingdom in 1898. Its population increased dramatically after the end of the Japanese occupation of Hong Kong during World War II, attracting mostly refugees fleeing the renewed Chinese Civil War. The walled city was crossed by alleyways, often only 1 to 2 metres (3.3 to 6.6 ft) wide, with poor lighting and drainage. Construction went unregulated, and most of the roughly 350 buildings were built with poor foundations and few or no utilities. The population was estimated at 33,000 in 1987, giving the walled city a density of around 1,255,000 per square kilometre (3,250,000/sq mi), making it the densest location in the world at the time. The walled city was demolished between 1993 and 1994 and the site is now occupied by Kowloon Walled City Park.Photograph credit: Ian Lambot