Hiroshima
Built on an Ōta River delta that made it Japan's military staging ground for continental wars. The flat terrain that attracted the military also maximized the atomic bomb's blast in 1945. Rebuilt within 13 years—now a 1.2M manufacturing city anchored by Mazda.
Hiroshima is defined by eight seconds on 6 August 1945—and by the centuries of geography that made those seconds inevitable. The city sits on the Ōta River delta, where six channels fan across a flat coastal plain before reaching the Seto Inland Sea. Mōri Terumoto built his castle here in 1589, exploiting the delta's natural harbour and defensible waterways. The Tokugawa shoguns who defeated Mōri kept the castle, and Hiroshima grew as a regional centre for the Chūgoku region. By the Meiji era, the city had become Japan's primary military embarkation point for continental Asia—its harbour and rail connections making it the logical staging ground for wars against China (1894) and Russia (1904). Imperial Headquarters moved here during the Sino-Japanese War. Hiroshima's military function sealed its fate.
The atomic bomb—Little Boy, a uranium gun-type weapon—detonated at 8:15 AM at 580 metres above the Shima Surgical Clinic. An estimated 80,000 people died instantly; the total by year's end reached 140,000. The flat delta terrain, which had made the city attractive for military logistics, also maximized blast damage—no hills to block the shockwave. The city was chosen partly because it had been spared conventional bombing, making it a clean experimental target.
Reconstruction began almost immediately. By 1958, Hiroshima's population had returned to pre-war levels. The Peace Memorial Park, designed by Kenzo Tange in 1955, turned the hypocenter into a permanent memorial visited by over 1.7 million people annually. Mazda (originally Toyo Kogyo), headquartered in nearby Fuchu, anchors the regional economy and employs tens of thousands. The city's manufacturing base—automotive, machinery, food processing—generates a metropolitan GDP exceeding ¥11.8 trillion. Hiroshima University, rebuilt after the bombing, is one of Japan's leading research institutions.
Hiroshima's population stands at 1.2 million in the city proper and 2 million in the metropolitan area. The city that was destroyed in eight seconds has spent eight decades proving that destruction is not destiny—though the Peace Memorial ensures that no one forgets the eight seconds either.