city, Hamgyŏng-pukto (North Hamgyŏng province), northeastern North Korea. It is located on Najin Bay, on the East Sea (Sea of Japan). Protected by Taech'o and Soch'o islands, it has a good natural harbour and is a port city. Formerly a poor village, it developed rapidly after the construction of the rail line connecting it with the urban centres of Manchuria in 1932. Fisheries are important; the neighbouring waters offer good fishing grounds for cod, pollack, and herring. Shipbuilding is carried on. It is a station on the rail line passing through Wŏnsan, to the south, through Hamhŭng and Ch'ŏng-jin, and continuing past Najin to Sŏnbong (Unggi) (Unggi), to the north, via the Ungna Tunnel (12,631 feet 【3,850 metres】 long), the longest tunnel in the country. Beyond Sŏnbong, the rail line parallels the Chinese border and then crosses into China. Pop. (2004 est.) 59,500.