The Hiro Naval Arsenal (Hiro Kaigun Kosho or Dai-Jūichi Kaigun Kōkū-shō (11th Naval Arsenal), often abbreviated as Hirosho) at Kure (呉), Hiroshima prefecture, was a production facility for seaplanes, flying boats, and aero engines for the Imperial Japanese Navy before and during World War II. It was largely destroyed in a raid by B-29 Superfortresses on 5 May 1945.