Jung Da-hyun is a reporter at The Korea Times, covering social issues in Korea, including foreign residents, education, environment and politics. Driven by a deep interest in people’s stories, she focuses on investigative and feature reporting through direct interviews and field coverage. She received the Amnesty International Korea Media Award for her “Deepfake Crisis at Schools” series. Reach her at dahyun08@koreatimes.co.kr. Always open to hearing your stories.
Underground tour reveals Seoul's hidden underbelly
People participate in a guided tour to a hidden space beneath Seoul Plaza, Friday. Korea Times photo by Jung Da-hyun
By Jung Da-hyun
By Jung Da-hyun
The Seoul Metropolitan Government has unveiled a mysteriously hidden yet huge underground space in the heart of the capital for the first time in 40 years, followed by its guided tour to the secret place.
Given that the space, located beneath Seoul Plaza, has remained hidden from the public for four decades, public interest in getting a firsthand look at the site is enormous. The city offered a limited run of guided tours, which were booked up with reservations within five minutes of being offered.
And the rare opportunity ― available only on Fridays and Saturdays until Sept. 23 ― seems to be worth it, according to visitors who said it was more impressive than they expected.
“I had initial expectations that it would be a simple exploration of the site,” said Oh Jae-hyun, 22, a university student who joined the tour on Friday. “However, it was much better given that we could venture into the unknown place with an informative narrative.”
Led by a docent explaining its history, visitors are guided through the hidden space.
The 50-minute tour starts at Taepyeong Hall, located on the basement floor of Seoul City Hall, and passes through Citistar Mall, Seoul's first underground shopping complex constructed in 1967, before venturing into the hidden space and circling back to City Hall Station.
While the city was aware of the space's existence, it was deemed unfit for public use due to the absence of natural light and ventilation, and the accumulation of dust, according to the Seoul Metropolitan Government.
“The historical information about the space was gleaned from newspaper articles but still, some parts remain speculative,” said Lee Jae-won, CEO of the Urban Architecture Station and tour docent.
People look around an underground space beneath Seoul Plaza during a guided tour, Friday. Korea Times photo by Jung Da-hyun
Access to this hidden space was granted through a door adjacent to the staircase connecting Euljiro 1-ga Station on Seoul Metro Line 2 and Citistar Mall.
This unique space was created during the construction of Line 2 in 1983, resulting from differences in floor heights required for connecting City Hall Station interchange of lines 1 and 2 and Citistar Mall.
The space itself is divided into two sections. The first section, closer to Euljiro 1-ga Station, features central columns spaced evenly to bear the weight of the roads and buildings above.
People participating in a guided underground tour pass by an electrical room, Friday. Korea Times photo by Jung Da-hyun
As visitors ventured further into this area, they encountered electrical rooms, drainage channels, trenches and intriguing stalagmite-like depositions formed by minerals contained in dripping water over decades. The electrical rooms remained in use until recently.
Continuing through the dim corridor, visitors arrive at a column-free expanse, stretching 12 meters in width, positioned beneath Seoul Plaza. Just above this space lies Citistar Mall, while below it, trains on Line 2 pass by at intervals of four to six minutes. Visitors can even feel the vibrations as trains pass beneath.
People go up a steep staircase leading to the end of the hidden space beneath Seoul Plaza, Friday. Korea Times photo by Jung Da-hyun
At the far end of this space, a steep staircase leads to the end of the hidden space. Upon ascending the stairs, one emerges in City Hall Station. This junction marks the point where the underground pathways of Line 1, established in 1974, and Line 2, inaugurated in 1984, converge.
From there, visitors return to the familiar subway passages currently used by the public. As they continue through the City Hall Station underground walkway, the tour eventually reaches the underground passage of Deoksu Palace, which was established in 1968 and transformed into the cultural space known as "Our Gallery" in 2019.
For those who missed the initial opportunity to sign up, on-site registration is available in case of cancellations for the day.
“We hope people provide various and creative ideas to transform this underused space after exploring it,” said Lim Jong-hyun, chief of the Urban Space Planning Division at the Seoul Metropolitan Government.