If Seoul is Korea's brain, the south is its appetite. This route strings together the open-air museum of Gyeongju, the seafood-and-neon port energy of Busan, the island-studded south coast, and a budget-flight hop to Jeju, the volcanic island Koreans themselves save up to visit. Ten to twelve days is right.
Gyeongju: the museum without walls
Start with the KTX from Seoul to Singyeongju (about 2 hours, 49,000 won) or arrive by bus from anywhere. Gyeongju was the capital of the Silla kingdom for nearly a thousand years, and its grassy royal burial mounds rise right out of the modern town like green whale-backs. Rent a bike (about 15,000 won a day) — the terrain is flat and the sights are scattered: the Daereungwon tomb park, the ancient Cheomseongdae observatory, and Bulguksa temple with its twin stone pagodas (grounds and buses a few thousand won each). At dusk, the Woljeonggyo bridge and Donggung pond light up and half the town turns out in rented hanbok. Guesthouses run 25,000-45,000 won, and Hwangnidan-gil street supplies the trendy cafes.
Busan: give it four nights
An hour south by bus or rail, Busan is Korea's second city and its most likeable — a pile of mountains, container cranes, beaches and fish markets. Stay near Seomyeon for transit or Gwangalli for the beach-and-bridge night view. Dorms 20,000-30,000 won. The essential circuit: Jagalchi fish market, where the ajumma vendors will fillet your choice and send you upstairs to eat it (a shareable raw-fish spread from about 30,000-40,000 won); Gamcheon Culture Village, a hillside of Lego-colored houses reborn from a slum into an art quarter; Haeundae beach; and the coastal walk at Igidae, where cliff paths stare across the water at the skyline. Two experiences we'd defend to the death: sunrise at Haedong Yonggungsa, the rare Korean temple built on sea rocks instead of a mountainside, and an evening in a pojangmacha tent eating tteokbokki and eomuk skewers among off-work salarymen. If your timing is right, October's Busan International Film Festival takes over the city.
Tongyeong and the south coast
Two hours west by intercity bus (about 12,000 won), Tongyeong is the base of Korea's southern archipelago — hundreds of islands scattered across a sea the government literally named Hallyeohaesang National Park. Ride the cable car up Mireuksan (about 17,000 won return) for the full island panorama, eat kkulbbang honey pastries by the harbor, and take a ferry to a car-free island like Somaemuldo for the tide-path walk to its lighthouse islet (ferries 10,000-25,000 won return). Tongyeong was also Korea's naval headquarters under Admiral Yi Sun-sin, whose turtle-ship replicas float in the harbor. One or two nights, guesthouses from 30,000 won.
The hop to Jeju
Bus back to Busan (or up to Sacheon) and fly to Jeju — carriers like Jeju Air and T'way sell the 55-minute hop for 30,000-70,000 won if you book a couple of weeks out, often cheaper than a long ferry once you count the hours. Jeju runs on rental cars, but backpackers manage fine with the island's buses (T-money works) plus the odd taxi.
Jeju and Seogwipo
Split your nights between Jeju City and Seogwipo on the south coast. The headline is Hallasan, South Korea's highest peak at 1,947 meters — the Seongpanak trail to the crater lake is a full day, free, but requires an online reservation now, so book before you fly. The east coast delivers Seongsan Ilchulbong, a tuff cone crater rising from the sea (about 5,000 won; do the dawn climb, the name literally means sunrise peak), and nearby you can watch the haenyeo — Jeju's free-diving women, many in their 60s and 70s — surface with shellfish and whistle their strange breathing song. Around Seogwipo: Jeongbang waterfall dropping straight into the ocean, lava-tube caves at Manjanggul, and black pork barbecue alleys where a proper feed runs 20,000-30,000 won. Dorms island-wide 20,000-35,000 won. Tangerines in winter, canola flowers in spring; Jeju always has a season going.
Practical notes
April-June and September-October are best; summer is typhoon-and-humidity roulette. Budget 80,000-110,000 won a day including the Jeju flight amortized. Book Hallasan and any DMZ-style timed entries ahead, use Naver Map for bus routing, and fly out of Jeju direct or hop back to Busan's Gimhae airport for onward connections to Japan — Fukuoka is closer to Busan than Seoul is.
