The essential museum in Hiroshima, and one of the most affecting in Japan. The two wings cover both the context of the bombing — Japan's militarism, the decision to use the bomb — and the physical reality of what happened in the city. The latter is not easy: charred clothing of a child who was walking to school, a watch stopped at 8:15, the shadow of a man burned into stone steps by the flash.
The building itself — a long raised block on pilotis, designed by Kenzō Tange in 1955 — frames a direct sight-line from the entrance to the A-Bomb Dome. Open daily 8:30–18:00 (to 19:00 July–August, to 17:00 December–February). Entry ¥200. Allow at least two hours.