Shanghai is one of the four direct-administered municipalities of China. The city is located on the southern estuary of the Yangtze River, with the Huangpu River flowing through it. The population of the city proper is the third largest in the world, with around 29.2 million inhabitants in 2023, while the urban area is the most populous in China, with 39.3 million residents. As of 2022, the Greater Shanghai metropolitan area was estimated to produce a gross metropolitan product (nominal) of nearly 13 trillion RMB. Shanghai is one of the world's major centers for finance, business and economics, research, science and technology, manufacturing, transportation, tourism, and culture. The Port of Shanghai is the world's busiest container port.