Hiroshima Castle , sometimes called Carp Castle , is a castle in Hiroshima, Japan that was the residence of the daimyō of the Hiroshima Domain. The castle was originally constructed in the 1590s, but was largely destroyed by the atomic bombing on August 6, 1945. The main keep was rebuilt in 1958, a replica of the original that now serves as a museum of Hiroshima's history before the Second World War, and other castle buildings have been reconstructed since.