The Atomic Bomb Dome survived because the blast fell almost directly above it, driving force downward through walls that would have collapsed under any angled shock. Its skeletal cupola, designed by Czech architect Jan Letzel and completed in 1915 as the Hiroshima Prefectural Industrial Promotion Hall, stands today at the northern edge of Peace Memorial Park in Nakajima-cho. Before 1945, this ground was not a park. Nakajima was a dense commercial quarter of shops, theatres and temples on a sandbar between the Motoyasu and Ota rivers. Roughly 6,500 people lived and worked here. The district vanished in seconds. When Kenzō Tange won the 1949 design competition for the memorial precinct, he did not rebuild the neighbourhood; he laid an axis through it, aligning the Cenotaph, the Flame of Peace and the ruined Dome along a single sightline that any hiroshima peace bike tour will cross within its first ten minutes. That axis explains why the city reads so well from a saddle. Hiroshima sits on a delta of six river channels, almost entirely flat, with wide riverside promenades and generous cycle-friendly boulevards laid out during postwar reconstruction. Peace Boulevard, 100 metres across, was intended as a firebreak and became instead a green corridor. Guided cycling tours through the Hiroshima landmarks link the park to Hiroshima Castle, rebuilt in ferro-concrete in 1958 after its 1589 original was levelled, and onward to Mitaki Temple in the wooded hills to the northwest, where three waterfalls give the site its name. The park's collections are deliberately restrained. The Peace Memorial Museum holds a stopped wristwatch, a school uniform, the shadow of a person on stone steps. Outside stand the Children's Peace Monument and the paper cranes folded by Sadako Sasaki's successors, replaced in their thousands each year. The rebuilt Rest House, the sole Nakajima structure still standing, now houses a basement room preserved as it was. What matters today is continuity rather than spectacle. The Flame of Peace has burned since 1964 and is intended to be extinguished only when the last nuclear weapon is gone. Entry to the park itself is free, at 0 JPY, open daily 09:00–17:00, with tour services priced separately by independent operators. A hiroshima peace bike tour tour therefore functions less as sightseeing than as a slow reading of a rebuilt grid — the reason so many visitors choose bicycle-based Hiroshima peace park tours over any single indoor stop.