Maizuru Naval District

Its territory included the entire Sea of Japan coastline from northern Kyūshū to western Hokkaidō.

The strategic importance of the location of Maizuru and its potential for development into a military port for operations in the Sea of Japan towards Korea, Russia and even China was recognized early by the Imperial Japanese Navy.

During the administrative re-organization of the navy in 1889, Maizuru was designated as the headquarters of the Fourth Naval District (第四海軍区, dai-yon kaigunku), and its harbor was dredged, a breakwater constructed and docking facilities for warships established.

In the post-war period, with Korea in Japanese hands, and the threats from Russia and China very much diminished, there were discussions about closing the military port.

The area today is occupied in part by facilities of the Japanese Maritime Self-Defense Force, which has preserved a portion of the original red-brick gates and a couple of buildings as commemorative museums.