Cheonggyecheon is a stream bisecting down town Seoul, South Korea. This stream has a length of 5.84 km(its trail-12.04 km long) and its greatest width is 84m. This stream is famous for restoration. It was a sewer of Seoul in the Joseon Dynasty. For half a century, industrial era after the Korean War, it had been entombed by pavement and had been a highway. After the restoration, Cheonggycheon has become an ecological park. The restoration of Cheonggyecheon took three years spending almost $400 million. Since its opening in 2005, hundreds of thousands of people have visited Cheonggyecheon with friends and family. Many interesting events have been often held at Cheonggyecheon as well.