Qingxichuan, an ugly duckling turns into a white swan. It used to be a foul ditch. It was polluted by the discharge of industrial wastewater and domestic sewage. Because there was no money to cover it up, shops and viaducts were built on it. With the progress of society, the Seoul government decided to re-treat Qingxi River, knock down the viaducts and shops, and re-treat the sewage. Only then did it have the clear rivers that are at the bottom today, and let Seoul citizens have a cool place. A good place to go. Qingxi River may also be a wake-up call to our country. After the tour, I actually saw a Korean anchor on the spot, big beauty!