The Beijing-Hangzhou Grand Canal is the earliest and longest man-made canal in the world. With a total distance of more than 1700 kilometers, it starts from Beijing and ends in Hangzhou. The Beijing-Hangzhou Grand Canal plays a great role in the development and exchange of economy and culture between southern and northern China, especially in the aspect of the industrial and agricultural development in the canal line area. It is called the "Great Water Wall", an allusion to the Great Wall. The Grand Canal crosses through Beijing, Tianjin, Hebei Province, Shandong Province, Jiangsu Province, and Zhejiang Province. It links five great water systems in China: Haihe River, Yellow River, Huaihe River, Yangtze River and Qiantang River.