The tidal bore of the Qiantang River is a world famous natural spectacle. It is caused by the combined effect of the gravitational force of the celestial body and the centrifugal force of revolving earth upon the funnel-like estuary of the river. 

When the tide surges at the beginning and middle of every month, it can whip up waves 2 - 3.5 metres in height, and there is a drop of eight and nine metres between tides. In the process the waves roar and charge forward like so many galloping horses.

An annual ritual takes place on August 18 of the lunar calendar year, which is the traditional tide-watching day when people throng to the Qiantang River to watch this amazing natural wonder. Watching the bores at the Qiantang River has been taking place each year for over 2,000 years. The observation area is at Yanguan Town where spectators can also have a glimpse into the traditional Chinese culture by visiting many other historical structures, such as the Sea-Pacifying Pagoda, the Temple of the Ocean God and Zhongshan Pavilion.