The Fukuyama Castle Keep built in 1622 was unfortunately destroyed by fire in the Fukuyama air raid of August 8, 1945. The stone walls that form the tower base have remained in their original state, even through the reconstruction in 1966 and the recent renovation work. These stone walls feature wedge holes called ya-ana hammered into the stone when it was being cut. The walls have been rounded by the burning of firebombs and parts show a red discoloration. Indeed, these stone walls seem to tell the history of the castle keep itself.