South Korea is compact enough for an efficient first trip but varied enough to feel like several holidays. Seoul gives palaces, markets, design, cafes, shopping, nightlife, and mountain edges. Busan adds coast, seafood, beaches, hillside villages, and a slower southern rhythm. Jeju Island brings volcanic landscapes, waterfalls, coast roads, hikes, cafes, and resort-style breaks.
Forum advice usually centers on pacing Seoul properly. The city is large, and neighborhoods have very different personalities. Stay near a subway line that fits your plans: Myeongdong is convenient, Hongdae is youthful, Gangnam is polished, and Jongno is closer to palaces and older streets. Busan is easy by high-speed rail and works well for two nights, especially if you want beaches, Gamcheon Culture Village, seafood markets, and temple views. Jeju needs a different mindset: public transport can be slow, so many travelers rent a car or hire day tours.
This guide suits travelers who want culture and comfort without losing access to nature. Build Seoul first, add Busan by train, then choose Jeju only if you have enough time for flights and island logistics. Spring and autumn are especially attractive, but winter city trips and summer beach plans can also work with the right expectations.