The Qiantang River is located in Hangzhou, Zhejiang Province, and is the largest river in China's Zhejiang Province; the major tides occur around the 16th to 18th days of the 7th lunar month each year. Due to the sun, moon, and Earth aligning in a straight line, creating immense gravitational pull, this triggers the tidal phenomenon. In addition, the Qiantang River estuary is trumpet-shaped, with the north and south banks about 100 kilometers apart, narrowing to about 20 kilometers at the Qiantang River mouth, and further reducing to just about 2.5 kilometers at Haining Yanguan. The dramatic width change causes the seawater to surge back, creating the spectacle of the "Qiantang Tide." With the combination of perfect timing and geographical advantage, such a wonder is formed. Along with the Amazon River and the Ganges, it is ranked among the world's three greatest tidal bores, with the Qiantang Tide even being called the "world's largest tidal bore."