What is the biggest city in Chongqing?

You are wrong. The largest city in China is Sansha City, which belongs to Hainan Province. Although the population of Sansha City is not as large as that of a town or even a village in Chinese mainland, it is only a few thousand people. But it is true that the people have their own mayors and deputy mayors. I have my own telephone area code and maritime police station in my own city, but the jurisdiction of my home is larger than that of any other city in China.