To ride anything at Lotte World, you need to put your bags down first. The good news: both the park's own lockers and the coin lockers at Jamsil Station are right there, connected underground.
Inside Lotte World and the mall
Lotte World Adventure and Lotte World Mall have coin lockers for stowing small items while you're on the rides or shopping. They suit day-bags rather than a full travel suitcase, and location and price vary by area — ask at an information desk if you have a big case.
Jamsil Station coin lockers — better for suitcases
For a full travel case, the coin lockers at Jamsil Station are easier. Jamsil connects directly underground to Lotte World Mall and Lotte World Tower (the Lotte Mall side, near Exit 1), so you can leave your bag and walk straight in. The lockers are spread across several spots in the station, so if one bank is full it's easy to find a free unit elsewhere. Check what's open by size on the Jamsil Station page before you go.
Prices are the standard Seoul rate — about ₩2,200 (small) to ₩4,400 (large) for four hours. Not sure your case fits? See locker sizes and prices.
Which to use
- Day-bag while on the rides: in-park / mall lockers.
- Full suitcase: Jamsil Station coin lockers (several spots, underground).
- Everything full: Jamsil also has a staffed T-Luggage desk.
Sources: Lotte World and Lotte World Mall facility guides. Coin-locker prices from the Seoul Metropolitan Government; spots and availability from Seoul Open Data.