Seoul is the latest cities to reclaim a piece of aging infrastructure for public use. Last month, South Korea’s capital city opened Seoullo 7017 Skygarden, an inner-city freeway transformed into a pedestrian artery and botanical garden.
The elevated public park was designed by Dutch architects and urban designers MVRDV as a series of gardens with 24,000 trees, shrubs, and flowers. Fifty plant families and 228 species and sub-species are organized according to the Korean alphabet along the pedestrian-only walkway.
Ben Kuipers, lead landscape architect on the project, said the unique arrangement highlights plant nuances. “The species are organized by genus and family. So people can experience the differences between species,” he wrote in an email. “There are small, themed gardens, like the maple garden and the pine tree garden, and a surprising contrast walking from family to family, in Korean alphabetical order.”
Over 600 concrete planters dot the approximately 3,000-foot linear park, which stretches across the city’s central train station and connects the Namdaemun market area to the east and neighborhoods to the west. Each pot has nameplate identifying the plants in both Latin and Korean. At night, the pots are illuminated in blue and white.
“The trees are the stars,” Kuipers said. “We turned the bridge into a ‘walk of fame’ with every tree in a pot like on a pedestal. And every season shows different features.”
With over one million visitors in the first 10 days, Kuipers said the high volume shows the concept resonates. “We wanted to create not just a pedestrian connection, but also a place to visit, be, and meet people. Therefore, we also added ‘activators,’ such as little shops and cafes.”
MVRDV won an international competition in 2015 held by the Seoul Metropolitan Government for the design of the park with their entry, The Seoul Arboretum.
The original freeway, known as the Seoul Station overpass, was built in 1970 at the heart of a city undergoing rapid economic and population growth. The structure was slated for demolition after a 2006 safety assessment determined it would soon be unsafe for vehicular use. Officials ultimately decided to recycle the freeway, incorporating the structure into its plan to make the city more walkable.
“This overpass has special meaning because it represents Seoul’s modernity,” Kim Joon Kee, deputy mayor of safety management for the Seoul Metropolitan Government, told CNN in 2016, as construction was underway. “It was built to relieve traffic congestion and, after 30 years, it became worn down, so we saw an opportunity for the city’s development.”
The name, Seoullo 7017, pays homage to the transformation of the freeway over time. The word Seoullo means “Seoul road,” and the numbers 70 and 17 reference its original constructed and when it reopened to pedestrian traffic, according to The Korea Times.
Implementing such a diverse planting design on an aging freeway structure came with a unique set of challenges. Kupiers explained there was little space for soil for the roots, given the load-bearing limitations and the inclination of the bridge destabilizes the soil. Designers also considered the safety of pedestrians and vehicles, ensuring no branches or trees would fall on the road or railway tracks below.
Furthermore, in a region with hot summers, cold winters, and typhoons, Seoul’s varied climate also posed a challenge. “We decided to create the right conditions for trees, shrubs and plants [by] making huge tree pots. These pots are isolated to prevent freezing and have a drainage, irrigation, and aeration system,” Kuipers explained.
The arrangement of over 600 pots, in varying sizes and depths, adds a distinctive, constructed quality to the design, a departure from the more organic style seen in many landscape designs in Asia, Kuipers said.
MVRDV’s design envisions the skygarden as an “urban nursery.” Kuipers said they plan to use the bridge in combination with the city’s own tree nursery to grow new trees and species, eventually distributing the pots along pedestrian routes in additional neighborhoods.
Seoul is hardly the first city to build an elevated urban walkway. Many have drawn connections between this project and New York City’s High Line. In fact, Seoul Mayor Park Won-soon was inspired by the famous James Corner Field Operations’ project, according to the The Korean Times. Still, the projects differ in their relationship to the surrounding urban fabric and the way they use plants.
“Although the High Line is a great example, Seoullo is different in many ways,” Kuipers said, noting the Seoullo Skygarden’s elevated views of the city and central location at Seoul Station in the heart of the city.