A simple black stone pillar marks the point directly beneath where the bomb exploded at 11:02 on 9 August 1945 — about 500 metres above ground. The surrounding park is small and easy to miss between the Peace Park and the Atomic Bomb Museum, but it is the most physically affecting site of the three. A surviving section of the original brick wall of Urakami Cathedral has been moved here and stands beside the pillar. Layers of geological strata cut into the ground show black soot lines from the firestorm that followed the blast.