Busan's old downtown, and the half of the city that isn't glass towers. A tight grid of covered market arcades, a working fish market on the water, a pedestrian shopping street, and a park on a hill with a tower on it — all walkable in an afternoon and all built, more or less directly, by Korean War refugees. Loud, cheap, wet underfoot, and where you eat rather than where you stay.
Who it's for: Anyone who wants to understand why Busan looks the way it does. Market eaters — this is the densest street-food ground in the city. History travellers: the provisional-capital story is legible on the pavement here. Budget travellers, since almost everything worth doing costs nothing or ₩8,000.