More cities should replace their highways with rivers - it worked for this one
How Seoul went from wartorn town to green metropolic
When I think of Seoul I think of a modern, technological city - as well as maybe BTS and tteokbokki.
It is also one of the world’s leading examples of urban revitalisation that put ecology and participatory democracy at the center of the city’s changes.
Seoul certainly wasn’t always this way.
After the destruction of the Korean War, the city (and the country) embarked on a rapid urbanization project often referred to as the “Miracle on the Han River”.
In roughly three decades, the country went from one of the poorest in Asia to an industrialized democracy at the forefront of the technological revolution.
Rapid industrialisation and urbanisation doesn’t come without its problems - which you can read further about here and here.
But, the Cheonggyecheon Restoration Project is emblematic of how Seoul transitioned first from a wartorn town, to an industrial city and finally to a modern green metropolis.
Breaking Ground
After the war, the Cheonggyecheon “stream” running through Seoul became a shanty-settlement for the downtrodden of the wartorn city.
As you might expect, the national and local governments weren’t so keen these settlements so they expelled them - and they also covered the stream with concrete in 1958.
In 1976, a highway was built on the covered stream which served the mega-apartment towers of the city.
By the 1990s, some of the infrastructure built during the recent urbanisation was failing and major construction disasters killed hundreds of people in Seoul.
These events, along with a growing displeasure with the state of the city by Seoul’s residents, and a new administration, lead to a major change in the city’s history.
The new Mayor, supported by a citizen’s committee, made the decision to rip up the highway and return the stream to the heart of the city.
Now, the open space running through the city has created notable environmental, social and economic benefits - as compared to a major highway.
According to researchers at USC, the environmental benefits include increasing biodiversity by more than 600%, better flood prevention, a 35% reduction of pollution in the area and offering residents temperatures up to 6°C cooler than on parallel roads.
The project has obviously taken cars off the road and encouraged an increase in public transport use, as well as bringing tourists and further investment to the area.
Maybe most importantly, however, is the imprint the success of the project left on the minds of the city’s residents and policy makers.
The project marked a clear turning point in Seoul’s history - moving from a grey metropolis to the modern green city we now know.
The city embarked on several other large scale green projects, like Seoullo 7017 which turned an overpass into a “skygarden” with more than 24,000 plants and greater pedestrian access to the city.
There are always drawbacks to major infrastructure projects like these, especially in countries where neoliberal capitalism is the dominant economic orthodoxy.
In Seoul’s case, the revitalisation of the city centre has led to skyrocketing housing prices and rapid gentrification, exacerbated by the countries persisting class system (i.e. Parasite).
In some cases at least, the city has been proactive in incorporating social concerns into green projects.
Building Together
In the early 2000s, outer villages and areas of Seoul began incorporating citizens into the decision making of their urban regeneration.
After some success, the national and city government of Seoul allowed local governments to build their own “urban regeneration master plans” (URMP) backed by public funding.
Somewhat surprisingly, many of the URMP’s of the outer regions were far more advanced ecologically than the policy of the city government - especially those of Jangwi-dong and Sangdo 4-dong.
Both regions designated either the protection of the climate or the environment as one of the three major goals of their URMP, meaning their policies had to follow suit.
Rooftop gardens, rainwater storage, creating urban green spaces and forestry and teaching ecological practices are just some of the policies that the regions implemented under their plans.
There are no statistics to reel off here about the success of these projects.
Rather, the success is measured by behaviour change in the city.
Residents of Jangwi-dong and Sangdo 4-dong remain engaged in ecologically centred regeneration projects.
Neighbouring regions independently took up similar policies to Jangwi-dong and Sangdo 4-dong.
In the end, the Seoul city government began requiring localities to include ecological policies in the URMP’s.
* * *
The story of Seoul’s green transition is both of major top-down projects as well as region-wide bottom-up ecological policy.
There are many other features of the cities-greening that didn’t get mentioned here - including significant green spaces (more than a quarter of the city) and one of the world’s best public transport systems.
As already mentioned, social inequities still persist as part of Seoul’s greening - mainly large-scale gentrification.
But at least the city, and the local residents, are taking a proactive approach to addressing the ecological crisis in their city - we can all learn from that.



Great example of how urban ecology and mobility reinforce each other.
There's growing evidence that greener streets don't just improve biodiversity or reduce urban heat—they also encourage people to walk and cycle more. The mechanism isn't only aesthetic: trees and green infrastructure make streets feel safer, more comfortable, and more inviting.
A recent systematic review in Frontiers in Public Health found consistent evidence that street greenery is associated with higher levels of active travel (walking and cycling). Another review published in Health & Place highlights that changes to the built environment can shift travel behavior at the population level—not just through education, but by making active modes easier and more appealing.
In other words, infrastructure shapes behavior far more effectively than awareness campaigns ever can.
For anyone interested:
• Frontiers in Public Health (2024): The impact of street greenery on active travel: a narrative systematic review — https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2024.1337804/
• PubMed (Health & Place): Do changes to the built environment influence walking and cycling? A systematic review — https://pubmed.ncbi.nlm.nih.gov/31301599/
• Free full text (PMC): https://pmc.ncbi.nlm.nih.gov/articles/PMC10936756/
Providence RI did it!