Apgujeong is Seoul's luxury-shopping and fashion quarter — Apgujeong Rodeo, the Galleria department store and the Cheongdam boutiques are all within reach. It is a neighborhood for walking and browsing, so leave your bag at Apgujeong Station (Line 3) first.
Coin lockers at Apgujeong Station
Apgujeong Station has T-Locker coin lockers at 2 spots, about 43 in total — about 26 near Exit 6 and about 17 near Exit 4. See each spot and the live count by size on the Apgujeong Station page.
Prices are the same across Seoul — about ₩2,200 (small) to ₩4,400 (large) for four hours, then hourly. English screen, pay by card, no ID. (Note this is Apgujeong Station on Line 3 — not Apgujeongrodeo Station on the Suin-Bundang line.)