Hongje Stream: Light Art, a Waterfall, and a Secret Walk Beneath Seoul
Last Updated on July 20, 2026
I used to pass through Hongje on a bus every day as I’d traverse from Eunpyeong-gu to a school in Seodaemun-gu. The area doesn’t seem like it’s changed much, but if you went through every day like I did, you’d notice small changes around the Yujin Arcade, the Inwang Market, and the Naebu Expressway area.
After teaching one day I traipsed up the mountainside to find the Ant Mural Village, and in the past couple of years there were more changes when the tunnels beneath the intersection were finally opened up and even renovated with light art. Hongje Stream is a beautiful place to walk or ride a bike in Seoul, it’s more locally known than mainstream popular, but that’s exactly why we love it.
Whether walked or biked, Hongje Stream in Seoul has some fantastic places to enjoy art and views while being surrounded by nature. Here’s what to find:
- The Stream Path and Art Pillars
- The Waterfall on Ansan Mountain
- Hongje Yuyeon: The Light Art Tunnel
- FAQ
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The Stream Path and Art Pillars
I used to ride my bike from the Han River north along the Hongje Stream that runs beneath the Naebu Expressway. It might not sound glamorous, but the stream that lies to the west of Hongdae, Yeonnam-dong, and Mangwon-dong has some fun features you don’t find on a lot of streams. The pillars that hold up the giant expressway must have been considered eyesores at one time, because a project began to decorate them and use them as more than just pillars supporting a highway above.
The giant concrete pillare were given a secondary purpose, decorated with artworks you would find in European museums, and turned the industrial pillars into an outdoor museum for the local community. As a local, I think it’s a fantastic example of considering how infrastructure can do more than just support the community physically.
The Waterfall on Ansan Mountain
Continuing on, there’s a waterfall. Yes, a waterfall in Seoul on the side of Ansan Mountain, which bursts into beautiful cherry blossom bloom each spring in Seoul. It’s one of my favorite places to take a hike and it’s even kid-friendly with wooden boardwalks and recliners. If you do take the kids, definitely check out the Seodaemun Museum of Natural History also on the mountain.
Before hiking up onto the mountain though, take a view of the waterfall from stream’s edge. This is also where you’ll find the viral Seoul cafe, Cafe Pokpo (카페 폭포). Pokpo is the word for waterfall in Korean. Manmade, this 60-meter wide and 25-meter tall waterfall was built in 2009 as part of the Hongje stream restoration project. I remember telling people there was a waterfall in the middle of Seoul and they didn’t believe me. Though manmade, it’s perfectly natural looking and really does create some beautiful ambiance.
How to get to Cafe Pokpo: From Hongje Station (Line 3): Head out of Exit 4 towards Bus 7738 until you exit the bus at Baekryeon Bridge (백련교). Cross the bridge towards Dongshin Hospital to find the cafe. Or if you prefer to take a stroll, take Exit 3 and walk straight until you see the scenic view of the waterfall cafe.
Address: 262-24 Yeonhui-ro, Seodaemun-gu, Seoul, South Korea (서울 서대문구 연희로 262-24)
Hongje Yuyeon: The Light Art Tunnel
Continuing on, I’d bike into Hongje-dong and then reach a tunnel where I’d have to turn around because it was blocked off. The 366-meter-long tunnel beneath the Yujin Arcade intersection was sealed off for years but that changed when the tunnel was reopened and transformed into a well-lit corridor with lanes for cyclists and pedestrians. Every inch of the tunnel has undergone renovations, creating a space where visitors can explore even the darkest corners.
About Yujin Sangga: The Yujin Arcade, Yujin Sangga, was built in 1970. It was originally designed not as a commercial space but as a potential tank encampment and defense line in the event of a military emergency, a relic of inter-Korean tensions and the anti-communist architecture of that era. This is something you can find all over Korea still today if you’re paying attention. The fact that it now houses a light art installation commemorating community and warmth rather than military contingency feels like an appropriately Seoul kind of transformation.
As you journey through the tunnel, spotlights guide your way, including at water-crossing points, casting colorful light patterns and 3D holograms. At the heart of the art exhibit lies “Warmth,” a series of 42 pillars standing in the water, adorned with color-changing LEDs that cast mesmerizing reflections in the gently flowing water.
This outdoor exhibition, known as Hongje Yuyeon in Seoul’s Seodaemun District, has turned the lower section of Yujin Sangga into an “Art Road of Light.” It’s a cool immersive art and interactive technology public space now. As visitors use these illuminated artworks as their guide, they re-emerge into the world we live in, appreciating the beauty of light and shadow amidst the surrounding darkness.
Hongje Stream, flowing through Seodaemun-gu, Seoul, before joining the Hangang River, has been beautifully developed over the years to provide a picturesque walking area for local residents. Similar to Cheonggyecheon Stream and Yangjaecheon Stream, the banks of Hongje Stream offer a delightful location for cyclists and exercise enthusiasts on the western end of Seoul. Stepping stones across the river and places for relaxation can be found along the stream’s path.
Step in from the entrance to the tunnel and you’ll find “Warmth,” created by Team Co-Work, which features 42 cement pillars adorned with lights that change color based on body temperature, offering an interactive and engaging experience. We were hot hot hot!
“Hongje Yuyeon Future Ecosystem” showcases wall paintings created by students from local schools, illuminating their artwork with LED lights. Other art installations along the waterway include “Light_Narrative of Light” by Mioon, “Hongje Yeonga, the Mise en Scene” by Jin Gi-jong, “Breath” by Team Co-Work, “MoonSun, SunMoon,” and “Um…” by Yoon Hyung-min, “Dudurukteo” by Youm Sang-hoon, and “Sound Art” by Hong Cho-sun.
It’s all very cool.
How to get to Hongje Yuyeon: Take the subway to Hongje Station and exit from Exit 4. Walk straight and the stream will appear at the main intersection ahead. Steps on either side lead down to the stream path. The tunnel entrance is visible from the water level, head north and you’ll find it without needing directions.
Hours: The exhibition is open daily from 10 a.m. to 10 p.m., with possible closures due to heavy rain.
FAQ
What is Hongje Yuyeon?
Hongje Yuyeon is a public light art exhibition in a 366-meter tunnel beneath the Yujin Arcade intersection in Hongje-dong, Seodaemun-gu, Seoul. It features interactive LED installations, 3D holograms, and artwork by multiple Korean artists, open daily 10:00am-10:00pm.
Is the Hongje Stream light art tunnel free?
Yes, completely free to enter and walk through.
How do I get to Hongje Stream and the light art tunnel?
Take the subway to Hongje Station, Exit 4. Walk to the main intersection, descend the steps to the stream, and follow the path north to the tunnel entrance.
Is Hongje Stream good for cycling?
Yes, the path runs along the stream with room for cyclists and pedestrians. The renovated tunnel has dedicated lanes for both. It connects to bike routes running south toward the Han River.
What else is near Hongje Stream?
Ansan Mountain, with a natural waterfall, cherry blossoms in spring, and the Seodaemun Museum of Natural History. The Ant Mural Village is a short climb up the mountainside from the stream area. Cafe Pokpo, a viral waterfall cafe, sits along the stream and is worth a dedicated visit.
The best Seoul discoveries are often those you find with your eye apps as I like to call them, sitting on a bus just looking out the window and something catches your eye and you follow the path to see what it is. Hongje stream is a perfect example of that. Grab a bike, or some good walking shoes and walk along the water and you’ll find plenty of things you’ll want to check out and look closer at.
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