Cheonggyecheon is a 10.9-kilometre-long (6.8 mi) stream and public space in downtown Seoul, South Korea. A natural stream sourced from the Suseongdong Valley in Inwangsan, it was historically maintained as part of Seoul's early sewerage until the mid-20th century, when post-Korean War rapid economic development and deteriorating conditions prompted the filling of the stream with concrete and the construction of an elevated freeway, the Cheonggye Expressway, in its place. In 2003, the city government began an urban renewal project to disassemble the expressway and restore the stream, which was completed in 2005 at a cost of over ₩386 billion.

The Downtown Seoul, also known as Seoul Central Business District or Sadaemun-An is traditional city center and central business district of Seoul, located through Gwanghwamun of Jongno District and Seoul Station of Jung District along the Sejong-daero and Jong-ro. For its time-honored and unique geographic status in Seoul, the Downtown is usually just called as 'The Central Business District ', or sometimes as 'Gwanghwamun Business District' for outstanding landmark 'Gwanghwamun' at the heart of it.