Seoul in spring or autumn is hard to beat. You get crisp air for wandering Gyeongbokgung Palace and cool evenings built for eating your way through Myeongdong night market. A week here usually runs about $3200 once you lock in flights, a central stay, and plenty of street food.
You do not need to drop that full lump sum today. Spreading the cost across a zero-interest window lets you book your big travel expenses now and pay them off in predictable monthly chunks before you leave or after you get back.
Remember that a 0% rate is a strict deadline, not free money. If you still have a balance when the 18 months end, the standard variable interest rate will apply to whatever balance remains. Set up auto-pay for $177.78 a month to finish on time.