The concrete monument commemorates all the people killed by the atomic bomb in 1945. It was designed by Tange Kenzo in the shape of a saddle which is supposed to "protect" the victims from the rain.
The cenotaph contains a list of all the A-bomb victims and an epitaph which reads: "Rest in Peace, for the error shall not be repeated". Come here to pay your respects.
Wikipedia (Japanese) http://ja.wikipedia.org/wiki/
More information at Visit Hiroshima http://visithiroshima.net/things_to_do/attractions/historical_places/canotaph_for_a-bomb_victims_memorial_monument_for_hiroshima_city_of_peace.html
Phone +81 82 242 7831
Address Hiroshima, Japan
Coordinates 34°23'34.715" N 132°27'9.264" E