The Seoul Metropolitan Government on Monday unveiled a 1.3 trillion won ($1.15 billion) project to build a mammoth underground public transit terminal in Gangnam by 2023 to alleviate road traffic in Seoul’s most congested area.





An artist’s rending of the mammoth underground facility to be built in Gangnam. Seoul Metropolitan Government.



Spanning 160,000 square meters of space across six basement floors, the Yeongdong-daero transit terminal is to be the single largest multifunctional underground complex to be built in the country, the city government said.



“A global consortium led by French architect Dominique Perrault has been selected for the complex’s design,” the Seoul Metropolitan Government announced Monday. Perrault is an architect known here for his work at Ewha Womans University -- the Ewha Campus Complex building.



Perrault’s “Light Walk” project was selected for its “compatibility to nearby districts and ability to digest massive traffic,” city officials explained.



Construction is to begin in 2019 and end in 2023.



Located between Samsung Station on Subway Line No. 2 and Bongeunsa Station on Line No. 9, the underground complex is envisioned to be a multifunctional, cultural and retail space while serving as a major transport hub in the southern part of the capital.



On the upper two levels of the complex, there will be an exhibition hall, a museum, a library and a shopping mall. The levels from the third underground floor down will be used as bus, subway, train transit and transfer centers and parking lots for tour buses.





An artist’s rending of the mammoth underground facility to be built in Gangnam. Seoul Metropolitan Government.



The complex will connect Subway Lines No. 2 and 9 with a direct transfer passageway, and offer a junction of five train lines including the high-speed KTX and bus stops.



The city expects at least 600,000 transit passengers will visit the underground terminal every day, nearly double the number at Seoul Station. Over 180,000 people are expected to take buses here, following the 2023 opening of a bus-only lane in the area.



Yeongdong-daero’s 480-meter sector of road will go underground and the surface area will be created into a 30,000-square-meter public plaza, which is double the size of Seoul Square in front of the City Hall building in Jung-gu.





An artist’s rending of the mammoth underground facility to be built in Gangnam. Seoul Metropolitan Government.