Hyesan is a city in the northern part of Ryanggang province of North Korea. It is a hub of river transportation as well as a product distributi…Hyesan is a city in the northern part of Ryanggang province of North Korea. It is a hub of river transportation as well as a product distribution centre. It is also the administrative centre of Ryanggang Province. As of 2008, the population of the city is 192,680.