Zaozhuang, the first city the Grand Canal meets when it enters Shandong province from the south, has the only stretch unchanged since the Ming Dynasty.

"Most docks and mooring points along the canal have been changed or renovated by modern development, but Zaozhuang has a 3-kilometer passage along which the docks and mooring points are original," Chen says.

The width is also unchanged, he says.

On paper, the Grand Canal runs 1,747 kilometers - making it nine times longer than the Suez Canal. Partsdate back to the 5th century BC.

The original canal system took shape during the Sui Dynasty (AD 581-618), the capital of which was Luoyang - now the second largest city in Henan province by GDP.

Sui emperor Yang Guang needed to transport grainfrom the fertile Yangtze region northward to support his court and armies. So the emperor forced a huge number of workers to build the canal to connect Luoyang with Beijing and Hangzhou, capital of today's Zhejiang province.

The Grand Canal didn't pass through Zaozhuang until the Ming Dynasty, when an east-west waterway called the Jia Canal was devised to circumnavigate the Yellow River's floods, which frequently paralyzed the Grand Canal.

"The Jia Canal is built according to its geographic features. Since it was completed, the Grand Canal has rarely been obstructed by the Yellow River, solving the biggest problem for emperors," Zaozhuang's Grand Canal culture promotion office expert Dong Yunqi says.