Reading this makes me so sad and reminded me of a book I read years ago: Hiroshima by John Hersey - about the first-person narrative account of survivors who witnessed the impact of atomic bomb dropped on Hiroshima that morning.
Shiroyama Elementary School
Nagai Takashi Memorial Museum Nagasaki
These felt much more personal than anything I saw in Hiroshima and there were zero (other) tourists to interrupt the experience (very much unlike the museum in Hiroshima).