The skeletal shell of the former Industrial Promotion Hall stands as the starkest reminder of August 6, 1945, when the atomic bomb exploded almost directly above it. Built by a Czech architect in 1915, everyone inside was killed, yet the building was one of the very few left standing near the epicentre. The decision to preserve this ruin as a memorial was controversial but profoundly right. Return at night when the crowds have gone and the propped-up remains are floodlit against the dark sky, and the silence becomes almost unbearable.