What is a Special Administrative Region of China that was formerly a British colony?

Hong Kong is a Special Administrative Region (SAR) of China that was formerly a British colony. It was ceded to Britain under the Treaty of Nanking after the First Opium War in 1842 and was established as a colony. In 1997, Hong Kong was handed back to China under the principle of "one country, two systems," which allows it to maintain a separate legal and economic system from that of mainland China for 50 years following the transfer of sovereignty.

While Macau is also a Special Administrative Region that was formerly a Portuguese colony, it is important to note that the question specifically asks for the region that was a British colony, making Hong Kong the correct answer. Shanghai, on the other hand, is a major city in China but has never been a British colony in the same way. Taiwan has its own unique political status and has not been classified as a Special Administrative Region but is claimed by China as part of its territory.