The Qiantang River is located in Hangzhou, Zhejiang Province, and is the largest river in Zhejiang, China. The major tides occur around the 16th to 18th days of the seventh lunar month each year. Due to the alignment of the sun, moon, and earth in a straight line, an extremely strong gravitational pull triggers the tidal phenomenon. In addition, the Qiantang River estuary is trumpet-shaped—the distance between the northern and southern banks is about 100 kilometers, narrowing to around 20 kilometers at the river mouth, and further down to just 2.5 kilometers at Yanguan in Haining. This dramatic change in width causes the seawater to surge back, creating the spectacle of the “Qiantang Tide.” With the combination of perfect timing and ideal geography, this wonder comes to life. Along with the Amazon River and the Ganges, it is named one of the world’s three greatest tidal bores, with the Qiantang Tide being referred to as the “world’s largest tidal bore.”