Sasebo Naval Base

Sasebo Naval Base in Sasebo, Nagasaki Prefecture, in northwestern Kyushu, was one of the four principal naval stations of the Imperial Japanese Navy, alongside Yokosuka, Kure and Maizuru. Sasebo Bay is deep, ringed by hills and entered through a narrow channel, and was regarded as an outstanding natural harbour. The Navy surveyed it in 1883, decided in 1886 to establish a naval district there, and formally opened the Sasebo Naval District on 1 July 1889, with responsibility for the waters west of Kyushu and the East China Sea.

The base acquired shipbuilding and repair facilities, drydocks, magazines, fuel storage, training establishments and a naval hospital. Its shipbuilding department was reorganized in 1903 as the Sasebo Naval Arsenal, which built and repaired warships and was the forerunner of today's Sasebo Heavy Industries. During the Russo-Japanese War Sasebo served as a sortie and supply base for the Combined Fleet, and the Hario radio towers, completed in 1922, were a key part of the Navy's long-range communications network.

In the Pacific War Sasebo was a fleet anchorage, repair base and logistics hub for operations in the East China Sea and Southeast Asia. On the night of 28–29 June 1945 B-29s carried out a large incendiary raid on the city; the urban area was heavily damaged and the naval district headquarters building burned, though underground air-defence command facilities survived. The Sasebo Naval District was abolished on 30 November 1945.

After the surrender the main part of the base was taken over by the US Navy as Fleet Activities Sasebo. It was an important rear base for United Nations forces during the Korean War and remains a major American installation in the western Pacific, alongside the Japan Maritime Self-Defense Force's Sasebo District. In 2016 Sasebo, together with Yokosuka, Kure and Maizuru, was recognized as Japan Heritage under the theme of the naval districts; brick warehouses and the Hario transmitting station are among the surviving former naval facilities. The active American and Japanese installations are not freely open, and visitors learn about the base mainly through public museums in the city and harbour cruises.