Where to go and why — the character of each place, how to reach it, and how many days it deserves.

Seoul is Korea's capital and a fast, layered city where 600-year-old palaces sit beside high-tech districts. Most visitors give it three to four days, arrive via the airport railroad, and base themselves centrally to ride the excellent subway.

Gyeongju is Korea's open-air museum, the thousand-year capital of the Silla kingdom, where royal tomb mounds, a UNESCO temple, and an old observatory sit within easy reach. One full day covers the highlights; arrive by KTX to nearby Singyeongju station.

Busan is Korea's second city and its biggest beach destination, a relaxed coastal counterpoint to Seoul. Two to three days covers its beaches, fish markets, and cliffside temple. Most visitors arrive by KTX in about two and a half hours from Seoul.