Qiantang River usually enters its tidal bore period in the seventh lunar month. There are more than 700 tides in the river every year, most of which are medium-sized or small. Big tides come at the beginning and end of each lunar month.

The Qiantang River, the Amazon River in South America, and the Ganges River in South Asia are known as the "the world's three strong tide rivers".

The effect of the moon, the sun and other celestial bodies on the sea water causes the tide. The horn shape of Hangzhou Bay and the huge sandbar at the mouth of the bay make the tides of the Qiantang River especially spectacular.

A magnificent one-line tidal bore soars along the Qiantang River in Hangzhou on Aug 16. [Photo provided to China News Service]