From a slain dictator's covert hideout to a forgotten subway station, secret bunkers have been lying for decades underneath the bustling city of Seoul.
Recently, some of these spaces were unveiled to the public for the first time under a special one-month tour programme. Although city-run tours of the "ghost station" in Sinseol-dong and the air-raid shelter underneath Gyeonghuigung Palace are to end this weekend, one underneath Yeouido, turned into a museum, will remain open for visitors.
A pair of purple doors hides a secret platform that has been sealed off to the public for over four decades underneath Sinseol-dong Station.
One floor below the busy Sinseol-dong station, this ghost station has been regularly awakened by passing trains, though, as those finishing the day's work run on its rails in the darkness on their way to the garage.
The platform was constructed in 1974, but the route plan changed and it has never been used by passengers.
On the wall at one end of the platform hangs a sign "11-3 Sinseol-dong," so dusty and worn that it is hard to make out, reflecting the time passed since it was put up.
Sinseol-dong station's secret platform did not arouse much public interest until location scouts for film and music videos became interested in its unique atmosphere and setting. The Korean film "Cold Eyes" and music videos by some of K-pop's most popular groups, such as EXO and Twice, were shot here prompting viewers to call the hidden platform "ghost station."
During the tour programme that runs through Nov. 26, the dark tunnel was opened to the public for the first time in 44 years. Registrations for the tour programme quickly filled up in October.
A Seoul City official said no decision had been made on its future use, including whether or not to hold the tours again next year.
Secret presidential hideout
In the financial district of Yeouido, a secret bunker is hidden below the Yeouido Bus Transfer Center, and is now being used as a public museum.
Nothing was known about the underground shelter before it was discovered in 2005, when the city was constructing the bus transfer centre there.
The 871-square-meter area was flooded when it was first found and it had sofa sets, a toilet and a shower booth inside.
The city looked into aerial photographs of the surface area taken in the past and finally concluded that the bunker was likely to have been constructed in 1977.
They also believe it was created as a secret hideout for the dictator at the time, Park Chung-hee, as it is located right below where the stage was placed for the Armed Forces Day event in 1977.
The city gathered ideas from citizens and turned the area into an art exhibition space, but left everything where they found it, except for installing safety and air conditioning facilities.
A box that was found full of keys is displayed there along with modern art pieces now.
The Seoul Museum of Art, which launched on Oct. 19, is open from Tuesday to Sunday from 10 a.m. to 6 p.m. and entrance is free.
Air-raid shelter underneath palace
Just below the historic Gyeonghuigung in Jongno is a secret air-raid shelter that is sealed off from the outside world by a thick, bluish iron gate.
This door, which stands out in the grassy surroundings, leads to a hidden space that dates back to South Korea's Japanese colonial period from 1910-1945.
Located below what used to be the site of the king and queen's bedroom, the underground shelter is thought to have been built in 1944 as an annex to the communication base station at that time. It appears to have been protecting the network facilities against possible air-raids during the warring period. Its outer concrete wall appears to be about 3 meters thick and the ceiling, 8.5 meters thick.
The site is left in its original state with its old, cracked walls and holes. It was discovered in the 1980s during excavation which was part of preparations for the restoration of Gyeonghuigung. The two-story area is divided into 10 rooms and a hallway, with the rooms ceilings open as to provide a view inside of the rooms on the second floor. On the attic-like second floor is a gate reduced to rubble, which is assumed to have connected the shelter with the palace.
Seoul City has installed special sound effects of the emergency siren and one resembling an air raid, to re-enact how it might have felt to use the shelter, and to add to the eerie and cold atmosphere.
The shelter is now managed by Seoul Museum of History. During the tour programme, 960 citizens visited. Previously the area was opened only for educational purposes for middle and high school students from 2014 to 2016.