Shanghai, with a population of more than 18 million (and over 5.8 million migrants), is one of the most populous and most developed cities in the People's Republic of China. Shanghai was the largest and most prosperous city in the Far East during the 1930s, and has remained the most developed city in China. In the past 20 years Shanghai has again became an attractive city for tourists worldwide. Shanghai is split in two by the Huangpu River. On the west bank is Puxi, the older city center, while the brand new development on the east side is called Pudong.