The Qiantang River in eastern China is known for the world's largest tidal bore, which is up to 9 metres (30 ft) high, and travels at up to 40 km per hour (25 miles an hour). It's a unique place in the world. A lot of people come to look at this amazing natural phenomenon. Sometimes humans get too close to Mother Nature and she makes them pay dearly. See these powerful images of tons of roaring water.