Seoul still has a Seodaemun District and a Seodaemun subway station, yet the actual “Great West Gate” is nowhere to be seen. Its official name was Donuimun, and it served as the western main gate of the walled capital. A gate was established around 1396, when the first city wall was completed, but difficulties involving terrain and roads led to changes in its location. The memory of a newly built gate—called Saemun or Sinmun, both meaning “new gate”—survives in the name Saemunan-ro, literally the road inside the new gate.
A city gate was not merely a wall blocking movement but infrastructure that managed passage
Donuimun connected the capital with regions to the northwest and carried flows of people, goods, and official information. Gate-opening hours, entry controls, roadside markets, and postal relay traffic helped set the rhythm of urban life. The wall was both a defensive structure and an administrative boundary; the gate was the controlled passage through it.
The form familiar from surviving photographs dated from the 1711 rebuilding
Donuimun went through construction, relocation, repair, and reconstruction. Photographs taken before demolition show the gate pavilion rebuilt in 1711 during the reign of King Sukjong. It is therefore misleading to say that one unchanged building erected in 1396 survived until 1915. The institution and location had a long history, while the final physical structure was the product of a later rebuilding.
The 1915 demolition placed modern traffic above architectural heritage
Under Japanese colonial rule, Donuimun was removed to widen the road and accommodate streetcars. Contemporary planning often regarded walls and gates as obsolete obstacles, and the dismantled materials were not systematically preserved. The broad intersection visible today is both useful infrastructure and a landscape created by a colonial remaking of Seoul that erased an older landmark.