Cheonggyecheon (Hangul: 청계천) is a 10.9 km (7.0 miles) long, modern public recreation space in downtown Seoul, South Korea. The massive urban renewal project is on the site of a stream that flowed before the rapid post-war economic development caused it to be covered by transportation infrastructure. The $900 million project initially attracted much public criticism but, after opening in 2005, has become popular among residents and tourists.
Cheonggyecheon is an 8.4 km creek flowing west to east through downtown Seoul, and then meeting Jungnangcheon, which connects to the Han River and empties into the Yellow Sea. During the presidency of Park Chung-hee, Cheonggyecheon was covered with concrete for roads. In 1968, an elevated highway was built over it.
The stream was named Gaecheon ("open stream") after the first refurbishment project to construct a drainage system during the Joseon Dynasty. The work, which included dredging and bolstering the banks of the stream and building the bridges, was carried out every 2~3 years during this period from the reign of Taejong, the third king of the Joseon Dynasty. King Yeonjo especially undertook the refurbishment work as a national project.