Imjonseong

{{Short description|Former fortress in Yesan, South Korea}}

{{Infobox historic site

|name=Imjonseong

|image=Imjonseong Fortress 2.jpg

|caption=Part of the remaining wall structure (2023)

|location=Yesan County, South Korea

|type=Fortress remains

|designation1=Historic Sites of South Korea

|designation1_offname=Imjonseong Fortress, Yesan

|designation1_date=1963-01-21

|designation1_number=90

|coordinates={{coord|36|35|32.3|N|126|46|32.1|E|region:KR_type:landmark|display=title,inline}}

|mapframe=yes

|embedded={{Infobox Korean name

| hangul = 임존성

| hanja = 任存城

| rr = Imjonseong

| mr = Imjonsŏng

|child=yes

}}

}}

Imjonseong ({{Korean|hangul=임존성}}) was a Korean fortress in what is now Yesan County, South Korea. It was designated Historic Site of South Korea No. 90 on January 21, 1963.{{cite web|url=https://english.khs.go.kr/chaen/search/selectGeneralSearchDetail.do?mn=EN_02_02&sCcebKdcd=13&ccebAsno=00900000&sCcebCtcd=34&pageIndex=1®ion=&canAsset=&ccebPcd1=&searchWrd=IMJONSEONG&startNum=&endNum=&stCcebAsdt=&enCcebAsdt=&canceled=&ccebKdcd=&ccebCtcd=|title=Imjonseong Fortress in Yesan|publisher=Cultural Heritage Administration of Korea|accessdate=13 September 2014}}

The fortress was built by Baekje, one of the Three Kingdoms of Korea, as an outpost, presumably against the invasion of Goguryeo. It was located at the top of the mountain and was surrounded by a thick wall reinforced by stone. The circumference of the wall was approximately {{convert|3|km|mi}}.

Currently, only remains of two gates, of a well, and of an unidentified building are present on the site.