Hiroshima Castle (広島城 Hiroshima-jō), sometimes called Carp Castle (鯉城 Rijō), is a castle in Hiroshima, Japan that was the home of the daimyō(feudal lord) of the Hiroshima han (fief). The castle was constructed in the 1590s, but was destroyed by the atomic bombing on August 6, 1945. It was rebuilt in 1958, a replica of the original that now serves as a museum of Hiroshima’s history before World War II.

(Ref: https://en.m.wikipedia.org/wiki/Hiroshima_Castle)

During the final months of World War II, the castle served as the headquarters of the 2nd General Armyand Fifth Division, stationed there to deter the projected Allied invasion of the Japanese mainland. The castle was destroyed in the atomic bomb blast of August 6, 1945, and for many years, it was believed the castle structure was blown away by the explosion that destroyed Hiroshima, but newly discovered evidence suggests the explosion only destroyed the lower pillars of the castle, and the rest of it collapsed as a result.[2]

The present tower, constructed largely of concrete, was completed in 1958.

(Ref: https://en.m.wikipedia.org/wiki/Hiroshima_Castle)