It is located at the province's northeastern tip and borders the Sea of Japan to the southeast.

"Riwŏn" is the official North Korean romanization of the county's name, using the McCune–Reischauer system.

Due to the silting of the mouth of the Namdae, Riwon was located a little inland by the 1950s, with a larger port named Kunsŏn.

Riwŏn county is divided into 1 ŭp (town), 3 rodongjagu (workers' districts) and 21 ri (villages): Machine manufacturing dominates the local economy, accounting for half of annual industrial production.

Agriculture is carried out in the plains and along the streams; major crops include rice, soybeans and maize.