Thursday marks the Mid-Autumn Festival in China, and while it’s tradition to wish upon the moon at its roundest and brightest, there’s also another sight to look out for... the tidal bores of Qiantang River.

The big waves attracted tens of thousands of tourists onto the banks of the Qiantang River in Haining City, in East China’s Zhejiang Province. Tourists burst into cheers at the "one-line tide" when waves rolled forward at the same speed to form one long, straight-line.

The bores usually start at the beginning of the eighth lunar month, and reach their peak on the eighteenth day. The world-renowned natural wonder is caused by the gravitational pull of the moon, and the funnel shape of Hangzhou Bay. As well as the Amazon in Brazil and the Ganges in India, the Qiantang River sees one of the world’s largest tidal bores.