Every autumn, one October evening, Hanwha lights up the night sky over Yeouido Hangang Park with the city's grandest fireworks show — a free spectacle that has drawn close to a million people to the Han River since 2000. International teams take turns choreographing fireworks to music above the water, with the main stage set before the 63 Building and equally dazzling views from Banpo Bridge, where the Moonlight Rainbow Fountain shimmers nearby. Locals stake out a patch of riverside grass hours ahead, spreading picnic mats and ordering 'chimaek' — fried chicken and cold beer — straight to the lawn. As dusk falls and the first shells burst overhead, the whole riverfront erupts in cheers.