Hangang Park (Banpo)

Banpo Hangang Park is widely considered the busiest stretch among Seoul's riverside parks, centered on Jamsugyo — a bridge whose name literally means 'submersible bridge,' built to go underwater during floods — flanked by lawns and walking paths.

The main draw is the 'Moonlight Rainbow Fountain': 380 nozzles along both sides of Jamsugyo spraying Han River water across 1,140m, once recorded as the world's longest bridge fountain, with lights and water synced to music.

Honest heads-up: this isn't something you can see anytime — it's a scheduled, seasonal show. It typically runs only from mid-March to late October, in the evening, across a few short sessions (usually 20-30 minutes each). It doesn't run at all in winter. Heavy rain or murky river water can cancel the show outright, and true to its name, Jamsugyo closes to cars and pedestrians when the river level rises.

Local tip: the best viewing spots are on Jamsugyo itself, the riverside lawn of Banpo Park, or looking across from Some Sevit (the floating islands). To avoid missing the show, the safest move is checking the day's schedule with the operations office (02-3780-0578) or the Hangang Park website before heading out.