For decades the Cheonggyecheon Stream in Seoul, South Korea, had been covered and was used as a road with highway overpasses.

From 2002 to 2005, the City of Seoul brought new life to the downtown area by enhancing the urban environment and incorporating more greenery. The restoration of Cheonggyecheon Stream led to the revitalisation of central Seoul, unleashing the potential for green public spaces. Storms and floods as well as heat waves were also better tackled as a result. 

By limiting the traffic in the city center and providing bypasses, Seoul was able to reduce the daily number of cars on its roads by 160,000. As a result, the amount of small-particle air pollution was also decreased by 35%.

The restoration of the stream created over 6 km of green corridors and 400 hectares of parks. Data taken a few years after its completion showed a 6-fold increase of indexed bird species, multiple new fish species found, and an increase in the number of catalogued plant species, from 62 to 308.

With its tranquil and rejuvenating atmosphere, the riverside park attracts 30,000 people every weekend.