Jinhae Guard District (Chinkai Naval Base)

The Jinhae Guard District (鎮海警備府, Chinkai Keibifu) was the Imperial Japanese Navy's principal naval installation on the Korean Peninsula, situated on the sheltered waters of Jinhae Bay in present-day Jinhae-gu, Changwon City, South Gyeongsang Province, South Korea.

The base's origins trace to January 12, 1904, when a provisional base defense unit was established on nearby Geoje Island at the outset of the Russo-Japanese War. The Japanese Navy recognized the strategic value of Jinhae Bay — a deep, naturally protected harbor commanding the Korea Strait — and relocated the facility to the mainland. In December 1904, it was redesignated as the Chinkai Bay Defense Force, then the Chinkai Defense Force in October 1907. On April 1, 1916, the installation was elevated to Fortified Port (要港部, Yōkōbu) status, and full-scale construction of a modern naval port and planned city began.

From 1910 onward, the Japanese authorities laid out Jinhae as a purpose-built naval town modeled on European grid plans, with wide boulevards, administrative buildings, and — most famously — extensive plantings of Japanese cherry trees (Yoshino cherry) along the streets and waterfront. The city's cherry trees remain one of the most visible legacies of the colonial period and are the setting for the annual Jinhae Gunhangje (Naval Port Festival), which draws over a million visitors each spring.

On November 20, 1941, just weeks before the attack on Pearl Harbor, the Jinhae Fortified Port was elevated to full Guard District (警備府) status — one of four such promotions that day alongside Ōminato, Makō (Magong, in the Pescadores), and Ryojun (Port Arthur). This upgrade reflected the base's critical importance for wartime operations. The Guard District maintained comprehensive facilities including port administration, engineering and repair shops, communications units, medical services, a naval air squadron (established October 1, 1936), and procurement departments. During the war, it served as a staging point for convoy escort operations in the Sea of Japan and Korea Strait, and provided maintenance and logistical support for fleet units operating in the western Pacific.

In the final months of the war, the base's role expanded further: a combined special landing force was organized on July 20, 1945, and harbor patrol units were established at Rashin (Rajin) and Chongjin ports on July 25, 1945, to counter the growing threat of Soviet naval intervention. The Guard District was officially dissolved on November 30, 1945, following Japan's surrender.

After liberation, the South Korean Coast Guard and subsequently the Republic of Korea Navy took over the Jinhae facilities. Today, Jinhae hosts major facilities and commands of the ROK Navy, including the Korea Naval Academy, as well as the U.S. Commander Fleet Activities Chinhae (CFAC). The base remains one of the most important naval installations in East Asia.