Wonsan Port (Genzan)

Wonsan (元山, Japanese: Genzan) is a port city situated on the coast of the Sea of Japan (East Sea) in present-day Kangwon Province, North Korea. The port was opened to foreign trade in 1880 under Japanese pressure, making it one of the first three Korean treaty ports alongside Busan and Incheon. Under Japanese colonial rule (1910–1945), the city was known as Genzan and developed into the principal commercial and strategic port on Korea's eastern seaboard.

The completion of the Kyongwon railway line in 1914 connected Wonsan to Seoul (Keijō) — the cross-peninsula Pyongwon line to Pyongyang (Heijō) was not completed until 1941 — transforming the city into an eastern distribution center for goods flowing between the Korean Peninsula and Japan. The port handled exports of rice, minerals, and marine products while receiving manufactured goods from the Japanese home islands. The city underwent significant industrialization during the colonial period, with Japanese-built infrastructure including modern port facilities, warehouses, and rail terminals.

In military terms, Wonsan's most significant role was as the home base of the Genzan Naval Air Group (元山海軍航空隊), established in the autumn of 1940 (the Japanese Wikipedia chronology gives October 1; November 15 is also widely cited) on the basis of the 15th Air Group. The unit was initially equipped with Mitsubishi G3M "Nell" medium bombers and Mitsubishi A5M "Claude" fighters. On December 10, 1941, aircraft from the Genzan Air Group participated in the sinking of HMS Prince of Wales and HMS Repulse off the coast of Malaya — the first time in history that capital ships under way at sea were sunk solely by air power. The unit went on to conduct operations over the Coral Sea and against Port Moresby. In September 1942, its fighter squadron was separated to form the 252nd Naval Air Group, and on November 1, 1942, the remaining attack squadron was redesignated the 755th Naval Air Group. A second Genzan Naval Air Group was later established in August 1944 as a fighter training unit, which ultimately participated in kamikaze operations during the Battle of Okinawa.

Beyond its aviation role, Wonsan's deep-water harbor provided anchorage and logistical support for Imperial Japanese Navy vessels operating in the Sea of Japan, serving as a waypoint for convoy routes between the Korean Peninsula and the Japanese home islands. The port's strategic position made it integral to Japan's wartime maritime logistics network in the region.

Following Japan's defeat in August 1945 and the subsequent Soviet occupation of northern Korea, Wonsan became part of the Democratic People's Republic of Korea. During the Korean War (1950–1953), the port was the site of a major amphibious landing by UN forces in October 1950, followed by a naval blockade and bombardment — the Siege of Wonsan — lasting from early 1951 to July 1953, described by the US Navy as the longest siege in modern American naval history. Today, the port remains one of the principal ports on North Korea's east coast and continues to serve both commercial and naval functions for the Korean People's Navy.