- Built: 1599, Môri Terumoto
- Destroyed: 1945
- Rebuilt: 1958 (tenshu)
- Other Names: 鯉城 (Ri-jou)
- Japanese: 広島城 (Hiroshima-jou)
Môri Terumoto began construction on a castle located on an island in the delta of the Otagawa (in Aki province) in 1589. The work on the moats and walls was finished in 1593, but it took until 1599 for the tenshu and other buildings to be completed. Môri called this part of his lands Hiroshima (wide island). Shortly after the Môri clan found themselves on the losing side at the battle of Sekigahara in 1600, this part of their holdings was given to the former Toyotomi loyalist, Fukushima Masanori. The castle suffered severe flood damage in 1617. Fukushima asked the shogunate for permission to repair this damage, but never received an answer. Undaunted, he proceeded with repairs in 1619. This provided the Tokugawa with the excuse they needed to strip Fukushima of this fief, moving him to a much smaller fiefdom near Kawanakajima. Hiroshima han was then turned over to the Asano clan who held it until the Meiji Restoration in 1871. As happened to many castles during this era, all of the buildings except for the tenshu were destroyed by the government (castles were seen as a potential center for rebellions against the Imperial government).
Emperor Meiji lived in the castle for seven months during the Sino-Japanese War of 1894-95, and during the Russo-Japanese War of 1904-05, the Japanese Supreme Command (daihon'ei) was relocated to Hiroshima in order to be closer to the warfront; the castle was used at that time as a barracks for troops.
The castle's most tragic entry in the annals of history came in 1945 when it was destroyed by the first atomic bomb. While some number of the buildings were completely obliterated, the tenshu was simply blown over and did not burn. Timber from the destroyed tenshu was then taken by people to form ad-hoc shelters and the like; an area near the castle grounds came to be known as the "castle slums," and remained in place for a number of years. The stone walls of the castle compound survived largely intact.
Plans were considered in 1946, though never completed, to erect a replica of the Statue of Liberty on the former site of the castle, as a symbol of peace, and as part of efforts to "purify" the castle site of its military associations, transforming the site instead into a "palace of culture and sports." Similar efforts, also emphasizing culture and sports, were considered, or undertaken, in many other cities.
Reconstruction of the tenshu was begun in 1958. Using the original plans for the castle, it is an exact replica of the original (albeit a concrete reproduction, not built through traditional construction methods) and is built on the original foundation. The tenshu measures 118 feet in height and is 5 stories tall. It is built in the opulent early Momoyama style. The interior space is devoted to a museum.
- Kodama Kota & Tsuboi Kiyotari, editors Nihon Joukaku Taikei-20 Volumes Tokyo:Shinjimbutsu oraisha, 1981
- Hinago Motoo Nihon No Bijutsu #54:Shiro Tokyo:Shibundo, 1970
- Schmorleitz, Morton S Castles In Japan Tokyo:Charles E Tuttle Company Inc, 1974
- Nihon no Meijo Kojo Jiten 1989
- Meaning "Koi castle" or "Carp castle," after the many koi (carp) in the moat. Ran Zwigenberg, Hiroshima: The Origins of Global Memory Culture, Cambridge University Press (2014), 128n121.
- Takashi Fujitani, Splendid Monarchy, UC Press (1998), 129.
- Oleg Benesch, "Japan's Modern Castles Episode Three: Hiroshima Castle (広島城)," YouTube video, 31 May 2020, 
- Ran Zwigenberg, "Citadels of Modernity: Japan's Castles in War & Peace," talk given at Temple University, Tokyo campus, 12 July 2017.