Cheonggyecheon Stream or as I call it 'The Canal' is a great urban project in the Central Seoul. It's10.9 km (6.8 mi) long green space with the river. It is, especially during the hot summer, a fantastic space to relax and cool down.
I love the canal because it is going through one of my favorite parts of the city. All the way from Dongdaemun Design Plaza, around Gwangjang market, close to Myeong-dong, Insadong, and the Gwanghwamun. If you will spend some time wandering around the central Seoul, there is no way you will miss the Canal.
Sometimes it is difficult to decide if you should walk next to the river or on the street filled with the small shops of local merchants.