In China, people often refer to the Yellow River as the River of Sorrow, due it being infamous for its unpredictable, devastating floods. Researchers have found evidence of people attempting to change the rivers natural course, beginning 3,000 years ago, using levees and flood mitigation systems. By 2,000 years ago the river would have been unrecognisable to its natural state. Massive dams and dykes are being constantly built along the river to try and contain it. Although 3,000 years ago levees seemed the best way to tame the river, they would eventually break down into sediments and deposited on the river bed, increasing the height of the river. Sadly, we continued to build levees to try contain the river after it rose, creating an ongoing cycle. The Yellow River is also being contaminated with industrial chemicals stemming from a coal mine, according to Greenpeace China.