Imjonseong Fortress

Imjonseong Fortress (예산 임존성) is a historic site located in Yesan County, South Chungcheong Province, South Korea. It is designated on January 21, 1963 under number 90.

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 3 km.

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