Much material heritage is marked by national memorials to war and its heroes. This article considers two examples that commemorate aspects of defeat, loss, and military disaster in war – the Australian War Memorial and attached museum and the museum and Peace Park at Hiroshima Japan. For Australians, the nation became a recognisable entity in the wake of disastrous defeat at Gallipoli in World War I. The physical manifestation of that heritage combines a solemn mausoleum with a massive and expanding museum that celebrates all Australia’s war contributions since then. For Japan, the peace park in Hiroshima focuses on the civilian heritage of the atom bomb Americans dropped in August 1945. Unlike the Australian Memorial, there is no celebration of war, soldiers, or militarism at the Peace Park. This article explores the differences, similarities, ironies, and contradictions of war heritages built out of crushing instances of loss rather than national moments of victory.