Ryanggang UK /ɹiˈæŋ.ɡæŋ/US /ɹiˈɑŋ.ɡɑŋ/ noun1 •A province of North Korea. Capital: Hyesan.Hyesan. The capital of the Ryanggang Province. Material was taken in a gorge, about 1000 m a.s.l., by the River Tuman-gang (China boundary) north-east of Hyesan (1 June). — 1984