5. Guangzhou
The biggest city in China's Pearl River Delta, Guangzhou is the manufacturing hub of southern China, which is in large part responsible for driving the country's decade-long, export-driven boom years. Today, Guangzhou epitomizes China's rapid urban growth and is home to a stunning opera house designed by Zaha Hadid and an innovative bus system that's trying to combat the city's massive traffic jams. When the cities of the Pearl River Delta -- with Guangzhou at its heart -- are connected into one giant megacity, the region will include some 40 million residents.
Above, policemen keep order outside the Guangzhou Railway Station on Jan. 30, 2008. A snow storm left more than 800,000 people stranded around the station.
China Photos/GettyImages
