Seoul opens 40-year-sealed subway passage as K-culture venue

Commuters passed above it for decades without knowing what lay beneath. Now, a 335-meter underground passage in the heart of Seoul has taken on a new identity.

Closed to the public for more than four decades, the tunnel connecting Euljiro 1-ga and City Hall stations on Seoul Metro Line 2 officially reopened Monday as K-Culture Station, launching with “COSMOS,” an immersive exhibition marking the 20th anniversary of K-pop group BIGBANG.

Inside the darkened space, large digital screens display colorful digital portraits of the members, while bright yellow crowns — a symbol long associated with BIGBANG — glow across the black floor. The exhibition reimagines the group's two-decade history through light, video and sound across 11 experience zones featuring media art, projection mapping, holograms and interactive displays.

“For more than 40 years, a 335-meter underground space lay closed beneath City Hall Station, one of the city’s busiest transit hubs,” Seoul Mayor Oh Se-hoon said, after passing through digital screens, music and mirrored installations at the K-Culture Station's debut exhibition.

“The city government opened it safely, while the private sector added technology and creative content, turning a place commuters once rushed through into a cultural destination worth visiting.”

Built in the early 1980s as part of work connecting subway stations at different elevations, the passage had largely remained unused. Its exposed concrete structure, pillars and tunnel-like layout were left intact as much as possible during the conversion, giving the exhibition a raw, industrial atmosphere.

The transformation is part of the Seoul Metropolitan Government’s “Fun Station” initiative, which aims to transform underused subway areas into places for something fun and useful.

The city government began the project in 2024 with the Runner Station at Yeouinaru Station on Line 5, where people can change, store their belongings and prepare for a run, followed by the Fit Station at Ttukseom Station on Line 2 for fitness activities and the Smart Move Station at Meokgol Station on Line 7, offering artificial intelligence (AI)-based health checks and digital sports activities such as indoor golf simulators.

This underground passage was first opened to the public on a limited basis three years ago, allowing some selected volunteers to enter and see it for themselves. As public interest over the space grew, the city government saw its potential as a new venue for residents and tourists, and developed plans for the site based on ideas collected from citizens.

After mapping out a specific plan to develop the site, city authorities set up safety systems, including ventilation, fire protection, evacuation routes and electrical facilities. Creative MUT, a private firm that produces immersive K-content, designed and operates the exhibition space. The company plans to bring in shows using up-to-date technologies such as AI, holograms and virtual reality, according to the city government. The city government said it will keep K-Culture Station open as a permanent cultural venue.

“COSMOS” is scheduled to run through Sept. 27, from 10 a.m. to 10 p.m. Visitors must book in advance through Naver. Following the opening day, it will be closed every Monday.

“We will uncover hidden spaces across Seoul and turn them into Fun Stations, where people can find something new to enjoy each time they visit,” the mayor said. “We will make them new attractions in Seoul for residents and K-culture fans from around the world.”