Seonyudo Park, Seoul: A Reclaimed Water Purification Plant from 1978 to 2000, Reached by Crossing the 469 m Seonyugyo Bridge

From the Water Purification Plant in 1978 to the Park on April 26, 2002 — The Structures Left by Seonyubong

Seonyudo is a midstream island on the Han River along Yanghwa Bridge, and its name carries the meaning of "an island where immortals play." In the Joseon Dynasty, it was known for its Han River scenery to the extent that Gyeomjae Jeong Seon left three true-view landscape paintings of Seonyubong, but quarrying during the Japanese colonial period and later development greatly altered the mountain's original form.

This island was the Seonyu Water Purification Plant, which supplied tap water to southwestern Seoul from 1978 to 2000. After the purification plant was relocated, the city of Seoul created a park by reusing the water tanks, sedimentation basins, and water supply pump room rather than demolishing them, and Seonyudo Park opened on April 26, 2002. With a total area of 110,407㎡, it is one of Korea's early examples of environmental regeneration, transforming the framework of an industrial facility into a public garden and exhibition space.

3 to 14 m wide, 469 m long Seonyu Bridge — The island's front gate is not Yanghwa Bridge, but a pedestrian bridge

When walking in from the subway, Seonyu Bridge, which connects Yangpyeong-dong's Yanghwa Hangang Park to the island, is the clearest entry route. Built in 2002 by French architect Rudy Ricciotti to commemorate the 100th anniversary of Korea-France diplomatic relations, this pedestrian-only bridge has a gently curved deck 469 m long and 3 to 14 m wide that leads all the way to the park entrance.

After crossing Seonyu Bridge, you are immediately connected to Seonyu Bridge Observatory and the Water Purification Garden. You can also reach the island from Yanghwa Bridge, but rather than an approach where vehicle and pedestrian flows mix, it is easier to retrace your steps by going back and forth via Seonyudo Station and Seonyu Bridge. A round trip alone is about 1 km, so if you plan to see the park interior as well, sneakers are more comfortable.

How Four Gardens Emerged from Filtration and Sedimentation Basins — A Park Route Read Through Water

If this is your first visit, it is best to walk in sequence from Seonyu Bridge Observatory to the Water Purification Garden, Aquatic Plant Garden, Garden of the Green Columns, and the Garden of Time in order to understand the park's background. The Water Purification Garden is a space created using the former filtration and sedimentation basin structures, and the Aquatic Plant Garden was designed so that you can observe the growth of aquatic plants that have purification functions up close.

The Garden of the Green Columns is where the roof of the filtration basin was removed and the columns were left in place. Vines were planned to wrap around the columns, leaving the concrete columns as the stars of the space. The Garden of Time is also based on the old sedimentation basins, and its composition of themed gardens such as aromatic plants, vines, color, and sound prevents the former water plant from being seen as merely an "old building."

• Water Purification Garden: A section where the old filtration and sedimentation basins are viewed together with aquatic plants
• Aquatic Plant Garden: A section for observing the growth and purification process of waterside plants
• Garden of the Green Columns: A filtration basin with the roof removed and the columns left standing
• Garden of Time: A section where the old sedimentation basins were transformed into multiple themed gardens

Free open from 06:00 to 24:00, Story Hall closed on Mondays — Viewing the park and exhibition space separately

Seonyudo Park is open every day from 06:00 to 24:00, and admission is free. The park itself is open year-round, and the management office phone number is 02-2631-9368. Official park information is available at https://parks.seoul.go.kr/template/sub/seonyudo.do, and for evening walks, plan to return toward Seonyu Bridge before closing time at 24:00.

The "Seonyudo Story Hall" inside the park is a facility that converted the former water supply pump room into an exhibition space. According to the Seoul Tourism Organization, it operates Tuesday to Sunday from 09:00 to 18:00, and from 09:00 to 17:00 in winter, and it is closed on Mondays. It was temporarily closed from July 10 to 12, 2026, for air-conditioner replacement, but the work was completed on July 12.

• Park: Daily 06:00-24:00
• Admission: Free
• Story Hall: Tue-Sun 09:00-18:00, winter 09:00-17:00
• Story Hall closed: Every Monday

Line 9 Seonyudo Station Exit 3, 782 m and transfer at Dangsan Station — The real choice for first-time visitors

The Seoul Tourism Organization's revised 2026 guide lists 782 m from Exit 3 of Line 9's Seonyudo Station to the park. It is a route of about 10 minutes on foot across Seonyu Bridge, and you will first see the Han River and Yanghwa Bridge from the bridge. The park's official English guide also explains it as about 10 minutes from Seonyudo Station and about 15 minutes on foot from Dangsan Station on Lines 2 and 9.

If you use Dangsan Station, you can take bus 5714 to Seonyudo from Exit 1 of Line 2 or Exit 13 of Line 9. The park's official guide also marks trunk routes 602, 603, 604, and 761, and branch routes 5712, 5714, 6712, 6716, and 7612 as lines serving the Seonyudo stop. If you have a lot of luggage or want to reduce the long walking section over Seonyu Bridge, getting off at the bus stop is practical.

Parking inside the island only for disabled vehicles, 393 spaces at Yanghwa Parking Lot 3 — Calculating car access separately

Only vehicles for disabled visitors can park inside Seonyudo Park, and regular passenger cars should use the Yanghwa Hangang Park parking lot. The largest, Yanghwa Parking Lot 3, is located at 26-8 Yanghwa-dong, Yeongdeungpo-gu, with 393 spaces, and the entire Yanghwa Hangang Park operates 501 spaces across 3 parking lots from 06:00 to 24:00. If you think of the park and the parking lot as the same facility, there will be extra walking time to the island entrance.

Parking fees at Yanghwa Hangang Park are 1,000 won for the first 30 minutes, then 200 won per 10 minutes, with a daily maximum of 10,000 won. It is open free of charge for three days: New Year's Day, Lunar New Year's Eve, and the day after, as well as Chuseok Eve, Chuseok Day, and the day after. Inside Seonyudo Park, there are designated accessible restrooms and disabled parking signs, and strollers can use Seonyu Bridge and the main walking paths, but some areas using the old purification plant tanks include stairs, so moving section by section is easier than trying to cover the observatory and all gardens in one loop.

Basic 60-90 minute route and extended 120 minute route — to Cafe Naru and Yanghwa Hangang Park

The basic time for calmly seeing only the park is 60 to 90 minutes. If you cross Seonyu Bridge and pass through the Water Purification Garden, Aquatic Plant Garden, Garden of the Green Columns, Garden of Time, Circular Theater, and Seonyujeong in order, you can combine the purification plant structures with views of the Han River. If you include a visit to Seonyudo Story Hall, 90 to 120 minutes is appropriate.

If you walk farther, you can extend the route to about 2 hours by continuing to Yanghwa Hangang Park outside the island. The park map shows Cafe Naru, a convenience store, a nursing room, infant and children's restrooms, the management office, the environmental classroom, the circular theater, and the metasequoia path. Bicycles and kick scooters are not allowed to be ridden inside the park for pedestrian safety, so if you are on a bicycle trip, it is best to switch to walking before entering Seonyu Bridge.

• 60-90 minutes: Seonyu Bridge round trip and the four gardens
• 90-120 minutes: Includes the Story Hall, Seonyujeong, and the Circular Theater
• About 2 hours: A route that adds a walk through Yanghwa Hangang Park