Shanghai has been the center of trade in China for 1,000 years. Once a booming fishing town, it is now China's biggest city. Shanghai's location on the East China Sea helped it become one of the largest seaports in the world. In the late 1990s, Shanghai underwent a major renovation to become a city packed with high-rise buildings, extensive freeways and people. More than 18 million people live there. (FREDERIC CIROU—GETTY IMAGES)