Seonyudo Park turns a former water-treatment plant on the Hangang into a river-island garden where retained structures, water, and planting reveal one another.
At Seonyudo Park, read the garden alongside the structures of the former drinking-water purification plant. The park occupies Seonyudo Island in the Hangang River at Yanghwadaegyo Bridge, but its identity is not simply island scenery. A water-purification plant once supplied drinking water to southwestern Seoul here. When the obsolete plant became a park, its structures were retained and reused. That history gives the visitor a more specific question than where to take a pause: what does a garden reveal when it does not hide the infrastructure that came before it? Seoul’s design connects four thematic gardens through a water-circulation system, and the city describes aquatic planting and ecological woodland alongside the retained plant structures. This desk-researched guide does not claim a personal visit, a current route, or live operational conditions. It offers a way to look instead: begin with the island, notice the former plant’s material presence, then follow the relationship between water, planting, and reused fabric.
FIELD NOTE 01
Read the island before reading the garden
Seonyudo Park sits on Seonyudo Island in the Hangang River at Yanghwadaegyo Bridge. The bridge, river, and island form more than a scenic surround; they give the park a physical context that is inseparable from its former purpose. This was not an inland garden later decorated with industrial remnants. The official record identifies a water-purification plant that supplied drinking water to southwestern Seoul, so the surviving built forms belong to a site that once served the city through water.
The park was created by retaining and reusing structures from the obsolete treatment plant. Instead of asking only which garden feature is most attractive, ask what earlier function remains visible and how it shapes the landscape now. The retained fabric is evidence, not stage set. It keeps the water plant from becoming a footnote and gives the island garden a distinct Seoul identity. The durable observation is the relationship between river location, former public utility, and garden reuse.
Compare the park at two scales: its island position beside Yanghwadaegyo Bridge, then the surviving structures of the water plant. The river and bridge locate the island; the retained treatment-plant structures distinguish the park's history from its wider setting.
FIELD NOTE 02
The former plant is the evidence, not the backdrop
The former purification plant is the clearest material clue to Seonyudo Park’s character. Seoul states that the plant supplied drinking water to southwestern Seoul and that its obsolete structures were retained and reused to create the park. These facts support a precise reading: the present landscape was made through transformation rather than erasure. The built forms matter because they come from a documented municipal function, and their continued presence gives the garden a visible past.
The facts are the plant’s earlier water-supply role, its obsolescence, and the reuse of its structures. An interpretation is that the park can be read as a record of Seoul changing its relationship with public infrastructure. Planting becomes more than decoration when it is seen beside retained water-plant fabric, and the old structures become more than ruins when their former purpose remains part of the explanation.
The retained structures can be read at two levels: their visible form is part of the garden view, and their documented history belongs to the former water-supply facility. Keeping those levels distinct lets you examine the structure you see without guessing the original function of each surviving piece.
FIELD NOTE 03
Follow water through the garden sequence
The design connects four thematic gardens through a water-circulation system. This is the key to reading water at Seonyudo Park as more than an atmospheric element. The system links the garden sequence to a site whose prior function was water purification, while the retained structures preserve a visible connection to that history. Here, water circulation refers to the published garden design; this account does not establish whether particular features are operating today. Rather, the design makes water a connective idea between an earlier municipal facility and a later public landscape.
Seoul also describes aquatic planting and ecological woodland alongside the retained plant structures. Together, these features make the site legible as a composed relationship rather than a set of unrelated zones. Aquatic planting directs attention to water as a living landscape element; ecological woodland provides another planted layer; reused built fabric keeps the transformation historically grounded. Instead of searching for one isolated highlight, allow the water-circulation design to connect what you see. That approach reveals why the garden sequence and the former plant belong in the same reading.
Compare the three elements shown in the accompanying illustration: the edges of retained concrete, the water surface, and the planting beside it. At the wider scale, the water-circulation design connects four thematic gardens; aquatic planting and ecological woodland provide two types of planted setting to compare within that design.
FIELD NOTE 04
Let the Time Garden slow the interpretation
The Time Garden is among the landscaped spaces named in Seoul’s description of Seonyudo Park. The garden belongs to a landscape created after the water-purification plant became obsolete, yet the park’s creation retained and reused that plant’s structures. It simply makes time visible in two forms: a present garden setting and an earlier water infrastructure that still shapes its frame.
Seonyudo Park's documented distinction is the union of former plant and landscaped space. At the Time Garden, or at another named landscaped point, the productive question is architectural as well as botanical: how does the garden sit beside the retained fabric of a site once built to supply water?
In the detail illustration, follow the narrow water element to its meeting with the concrete wall, then compare its regular edge with the planting beside it. This close view suggests an observation to make at the Time Garden: examine how a retained structure and the garden occupy the same frame.
FIELD NOTE 05
A river park with a former civic function still visible
A useful final comparison at Seonyudo Park separates water's former civic function from its role in the garden design. Drinking-water supply to southwestern Seoul describes the plant's former service to the city; circulation among four thematic gardens describes the later landscape design. The retained structures link those uses by giving the garden material inherited from the former plant.
For the garden itself, compare water, aquatic planting, and ecological woodland as distinct elements within the reused site. Notice their relationship to the surviving structures before treating them as a single scene of greenery.
You can make that comparison in a wide view of the river-island setting or a closer view of a retained structure. What matters is the change of scale: use the wider setting to locate Seonyudo, and the closer view to examine how the former plant remains within the garden.
Official information
Seoul Metropolitan Government
Seoul Metropolitan Government
Read Seoul’s 2019 description of the park’s aquatic planting, ecological woodland, and Time Garden; check a current park notice separately for visitor arrangements.
Seoul Metropolitan Government
Seoul Metropolitan Government
Read the official account of the former purification plant and its transformation into Seonyudo Park.