Unsan-à Âp is the town in Unsan County, North Pyongan Province, North Korea. The former name Onjà Âng-ri was reorganized to Unsan-eup in 1954.
Onjà Âng was a ri from 1949 to 1954.
In October 1950, Onjà Âng was the location of the Battle of Onjong, the first contact between Chinese and United Nations Command forces in the Korean War.