This area near the hypocenter was strewn with corpses after the bombing. Many corpses, including those pulled out of the river, were brought here and cremated.
In 1946, individual donations enabled the construction of a temporary memorial mound, a temporary vault, and a chapel. Ten years later in 1955, Hiroshima City took over the project and rebuilt the decrepit vault. Unclaimed ashes that had been kept in various other places were also brought to the new vault. The vault lies under the mound and contains the ashes of roughly 70,000 victims. These were persons whose ashes were unclaimed because the entire family perished or persons of unknown identity.