http://money.cnn.com/gallery/news/2014/07/08/china-high-speed-rail/index.html

In the six years since China opened its first high-speed rail line, the country's network has grown to 6,800 miles of dedicated track -- making it by far the world's largest system.

The scale of the project is simply massive, but it has also produced hundreds of billions of dollars in debt, a deadly accident and allegations of corruption.

The extensive network connects just about every major city in eastern China -- from Harbin in the north to Shenzhen, near the border with Hong Kong.

Trains cover the 820 miles between China's two largest cities -- Shanghai to Beijing -- in just five hours. Since the line opened in 2011, more than 220 million passengers have traveled the route.

If 6,800 miles of high speed track isn't impressive, just wait for China's next trick.

Beijing plans to double the network's size in a few years, including a line connecting central China with the restive Xinjiang region in the far west.

While the economic benefits of the link are questionable, the new line will cut travel time between Lanzhou and Urumqi to eight hours from 21 hours.