The county is called by the name Eunyul (은율) in South Korea, due to the pronunciation differences between Northern and Southern Korean dialects.

Neolithic artefacts were found in the region then known as Gunryanggol village located in the subdivision called Changam-ri Nambumyeon (now forming part of Sandong-ri).

Bronze age Dolmen were found in different parts of the County, and many bronze age artifacts and Chinese knife money during the Han dynasty were found in the region in the mud tombs.

The Unryul iron mine, located north of Unryul-ŭp, is one of North Korea's leading sources of iron ore. A 4.6-kilometre (2.9 mi) belt conveyor, built in 1975, carries waste rock from the mine to the coast.

The rock has been used to build dikes between offshore islets and reclaim shallow bays for farming, fishing and salt evaporation.