The Beijing-Hangzhou Grand Canal appears on the list of UNESCO World Heritage Sites. This Canal is the longest canal, or artificial river in the world and the desired tourist destination. It starts at Beijing and passes through to several provinces to Hangzhou. This canal links the Yellow River to the Yangtze River.
The total length of the canal is 1776 km. The greatest height is at the mountains of Shangdong and its summit of 42m or 138ft. They had invented pound locks in the 10th century and was able to reach those heights.
The earliest type of lock is the flash lock, with its origins in China and used as long ago as 50 b.c. It had one gate and later a second gate added and the beginning of a pound lock. The first known example showed up in China in 984 a.d and had much more control of the water flow.
The first pound lock in Europe made its appearance in Vreeswijk, the Netherlands in 1373. This system, some with guillotine gates, took off in Europe and became the basis of the modern lock system.
Leonardo da Vinci, around 1486, improved the form of pound lock by designing a V-shape to the gate when closed. Because of the mitre-shaped gates, they were self-sealing from the pressure of the upstream water.
The larger international locks are mostly guillotine-type gates
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