Unjon County is a kun, or county, in North Pyongan province, North Korea. It borders Taechon to the north, Pakchon to the east and southeast, and Chongju to the north. To the south, it looks out on the Yellow Sea. Unjon was created in 1952 from portions of Pakchon and Chongju, and subsequently reorganized in 1954 and 1958. The terrain is relatively gentle, with low mountains in the west and plains to the south and east. The highest of the western peaks is Mogusan (414 m).