Nanjing ( listen), formerly romanized as Nanking and Nankin,[3] is a city situated in the heartland of the lower Yangtze River region in China, which has long been a major centre of culture, education, research, politics, economy, transport networks and tourism. It is the capital city of Jiangsu province of People's Republic of China and the second largest city in the east China region,[4] with acreage about 6600 square kilometers and a total population of 8,230,000.[5] The inner area of Nanjing enclosed by the city wall is Nanjing City (南京城), with acreage of 55 km2, while Nanjing Metropolitan Region includes surrounding cities and areas, with acreage over 60 thousand km2 and population over 30 million.