Columbia subject headings:
City walls--Korea (South)--Seoul.
Hanyang Tosŏng (Seoul, Korea)--History.
Seoul (Korea)--History.
Harvard subject headings:
City walls--Korea (South)--Seoul--History--Pictorial works.
City walls--Korea (South)--Seoul--History.
Historic sites--Korea (South)--Seoul
Historic sites--Korea (South)--Seoul--Pictorial works.
Princeton subject headings:
City walls--Korea (South)--Seoul--History--Pictorial works.
City walls--Korea (South)--Seoul--History.
Historic sites--Korea (South)--Seoul--Pictorial works.
Historic sites--Korea (South)--Seoul.