The Qiantang River east China's Zhejiang Province is known for the world's largest tidal bore. As tidal bores are caused by the stars and planets' gravitational pull, now is the best time to admire them. Scores of tourists from across China flocked Zhejiang's Haining City on October 4, the third day of the eight-day break for National Day and Mid-Autumn Festival, to snap photos of the spectacular phenomenon.