This is an example of how public investment in an area of a city that needs attention can be a catalyst for other developments. The area around the site is already coming alive. I think a project like this is good for Seoul; a city that has another kind of urbanism. It’s exciting to walk along the overpass and through the parks. The technical aspect of installing greenery on top of a structure from the 1950s, built originally with bad concrete and a load-bearing system that wasn’t efficient, was a big challenge. With the focus of city architects and the mayor, and a great collaboration with local government, we’ve been successful in delivering something that I really like.

What inspired the idea to create this park in the sky?
In 2014, we started discussing the idea because of concerns about the safety of citizens. The Seoul Station Overpass – which was built in 1970, crossing east and west of Seoul Station to relieve traffic congestion – was no longer able to serve as a road, despite continuous maintenance. Initially, the city government had considered demolishing it, but we finally came up with the idea of reusing it as a pedestrian-friendly walkway. This decision resolved its safety problems.

Seoul is a city where tradition and modernity harmoniously co-exist. What Seoul needs is urban regeneration that restores historic buildings and connects cultural heritage, rather than the kind of construction and development it has seen in the past. Based on these values, we intended to revitalise the surrounding area through the addition of the walkway, while preserving the historical features of the Seoul Station Overpass.

Do you think there’s potential for cities wanting to reuse their existing infrastructure in this way?
Yes, there are many opportunities for other cities that want to reuse their existing infrastructure instead of getting rid of it. Reusing existing infrastructure will make cities realise that 21st century sustainable growth strategies create future value through a paradigm shift that complements and integrates preservation and change in the city.

What’s been the reaction?
The Seoullo 7017 is a symbol of the transformation of Seoul from a development-centred city into a renewed, sustainable one. But it's the starting point of this transformation, not the end. We expect citizens and visitors to now walk around downtown Seoul in 20 minutes using the Seoullo 7017. With Seoul’s aim of becoming a walkable city, this garden will improve citizens' quality of life and revive the local economy.