Danyang-Kunshan Grand Bridge, China

The Danyang-Kunshan Grand Bridge in China, completed in 2010, is the longest bridge in the world at 164.8 km, carrying the Beijing-Shanghai High Speed Railway. Built in just four years using 450,000 tonnes of steel and 2.3 million cubic metres of concrete, it cost an estimated $8.5 billion and required 10,000 workers. It crosses rice paddies, rivers, and Lake Yangcheng.