Hong Kong, a special administrative region of China, is located to the east of the Pearl River estuary on the south coast of China. The region is bordered by Guangdong Province to the north and the South China Sea to the east, south, and west. Hong Kong developed initially on the basis of its excellent natural harbour and the lucrative China trade, particularly opium dealing. It was the expansion of its territory, however, that provided labour and other resources necessary for sustained commercial growth that led to its becoming one of the world’s major trade and financial centres. The community remains limited in space and natural resources, and it faces persistent problems of overcrowding, trade fluctuations, and social and political unrest.