A diplomatic loophole left one 2.6-hectare block of British Hong Kong under nominal Chinese sovereignty and effectively no one's law. By the 1980s the Kowloon Walled City held some 35,000 people in a single fused mass of 300-odd interconnected towers — the highest population density ever recorded — with its own water, wiring, unlicensed dentists, and rooftop playgrounds. It was demolished in 1993-94.