Shenzhen is a major city in the south of Southern China's Guangdong Province, situated immediately north of Hong Kong Special Administrative Region. The area became China's first—and one of the most successful—Special Economic Zones. It currently also holds sub-provincial administrative status, with powers slightly less than a province.Shenzhen's modern cityscape is the result of the vibrant economy made possible by rapid foreign investment since the institution of the policy of "reform and opening" establishment of the SEZ in late 1979, before which it was only a small village. Both Chinese citizens and foreign nationals have invested enormous amounts of money in the Shenzhen SEZ. More than US$30 billion in foreign investment has gone into both foreign-owned and joint ventures, at first mainly in manufacturing but more recently in the service industries as well. Shenzhen is now considered one of the fastest-growing cities in the world.Being southern mainland China's major financial center, Shenzhen is home to the Shenzhen Stock Exchange as well as the headquarters of numerous high-tech companies. Shenzhen is also one of the busiest container ports in China.