咸北線
In terms of regional characteristics, the Hambuk Line passes through two largely distinct areas. It runs inland in mountainous terrain between Panjuk to Hoeryŏng, then along the Tumen River and the northern border of the country all the way to Rajin. The steepest part of the line is between Puryŏng and Ch'angp'yŏng, where the ruling gradient is over 20‰. Conversely, the route on the Tumen River's bank along the national border is comparatively flat.