Landmarks & buildings
Gwanghwamun
Main gate of Geongbokgung Palace (also known as Kyŏngbokkung Palace)
Wikipedia names Gwanghwamun as where 2 films and series were filmed; each title’s page links to the sentence that says so. Wikidata records no shoot here yet. Newspapers, film offices and archives name more, listed below.

Filmed here, per Wikipedia
Wikipedia says these were filmed in Gwanghwamun. Each title’s page links to the sentence that says so.
From published sources
Newspapers, film offices, archives and city filming permits say these were filmed at Gwanghwamun. Each source is linked.
Filming locations nearby
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Landmarks & buildings
Gyeongbokgung Station
South Korea · under 1 km
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Streets & squares
Gwanghwamun Plaza
South Korea · under 1 km
Public open space in Downtown Seoul
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Towns & cities
Jongno District
South Korea · under 1 km
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Landmarks & buildings
Sejong Center
South Korea · under 1 km
Arts centre in Seoul, South Korea
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Castles & palaces
Gyeongbokgung
South Korea · under 1 km
Palace in Seoul, South Korea
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Towns & cities
Naeja-dong
South Korea · under 1 km