JMSDF Sasebo Museum, Naval history museum in Sasebo, Japan.

The JMSDF Sasebo Museum, nicknamed Sail Tower, is a seven-storey building. Its lower two floors reuse part of the former Sasebo Suikōsha officers' club, with a projecting stone-clad octagonal roof facing Kokusai-dori; floors three and up are glass-walled, and the open steel lattice on the roof resembles a ship's sail. About 1,300 of its 4,400 items are on permanent display.

The museum opened in 1997 and preserves records documenting Japan's naval forces from the Imperial Navy period through the creation of the modern Self-Defense Force. Its collections span the transformation of Japanese maritime defense across more than a century.

The museum reflects how Japan's naval forces have shaped the country's approach to maritime security and regional relations. Through its collections, visitors can observe the evolving role of the navy in Japanese society and defense.

Visitors ride the elevator to the seventh-floor observation post first, then descend one floor at a time, so allow time for the full route. The museum closes on the third Thursday of each month and from 28 December to 4 January. About 20 cars and 6 large buses can park free of charge; the site is a one-minute drive from the Sasebo Chuo interchange.

The building's nickname, "Sail Tower", comes from the angled steel lattice on the roof, which resembles a ship's sail. The museum occupies a seven-storey structure whose lower two floors reuse part of the former Sasebo Suikōsha, an officers' lodging and welfare facility of the old navy; its stone-clad octagonal roof projects toward Kokusai-dori. Visitors ride the elevator to the 7th-floor observation point and descend one floor at a time.