Jeju City in 3 days

Seongsan Ilchulbong (성산일출봉 — Sunrise Peak; Seongsan-ri, east Jeju; UNESCO World Natural Heritage 2007; a volcanic tuff cone (the technical name for an explosion crater formed by underwater volcanic eruption into the seabed (phreatomagmatic eruption) — the hot magma contacted the seawater, causing a violent steam explosion that blasted the surrounding rock into the air and the falling debris formed the rim of the crater without producing a central lava flow); the resulting formation: a 180m-high horseshoe-shaped crater open to the sea on one side (the crater was originally a complete ring but the sea has eroded the eastern wall); 90,000 m² of crater area, with 99 columnar basalt rock peaks around the rim; the sunrise from the crater rim (accessible via a 20-min climb, ₩2,000 entry) is the most famous natural spectacle on Jeju Island (the Korean name (il = sun, chul = rise) reflects this); arrive by 05:30 in summer to secure a rim viewing position. The haenyeo dive in the waters directly below the crater at low tide.

Manjanggul (만장굴 — the longest lava tube in Asia and one of the finest in the world; UNESCO World Natural Heritage 2007; total length 7.4km, of which 1km is open to public access); formed 250,000–300,000 years ago by the same eruptions that built Hallasan: lava flowed down the volcano's flanks and the outer surface solidified while the interior remained liquid, draining out and leaving the tube; the accessible section is an extraordinary underground world: a ceiling 5–7m high, with lava stalactites (formed by dripping molten lava that solidified before reaching the floor), lava falls (smooth surfaces where lava flowed down a step in the tube floor), and the Lava Column at the end of the accessible section (a 7.6m lava stalagmite, the largest in the world). Year-round temperature inside: 11°C (bring a light jacket in summer). Entry ₩4,000.

Jeju Folk Village Museum (제주민속촌박물관 — Seongup Folk Village, Pyoseon-ri; the most complete preserved traditional Jeju village in Korea (not a reconstruction — the village was preserved in situ rather than rebuilt)); traditional Jeju houses (the jeju jeogtong (제주전통 — the basalt stone house with a thatched roof (roof made from Phragmites australis reed grass, tied down with rope over a wooden frame), with the distinctive 'house snake' (jipgeoji (집게지)) — a harmless rat snake that traditionally lived in the thatch and was considered a guardian spirit); the village has 117 traditional houses, a shaman shrine (musok신당), and craft demonstrations (tteok (rice cake) making, fishing net weaving, Jeju pottery). Entry ₩12,000.

The Jeju east coast: the drive from Seongup Folk Village north to Seongsan (30km, 40 min on the coastal road (local Route 1132)) passes: the Jeju Haenyeo Museum (해녀박물관 — Gujwa-eup, 30km east of Jeju City; the definitive museum of the haenyeo free-diving tradition; collection includes original diving equipment (the old cotton suits before wetsuits were introduced in the 1970s), photographs, and oral history recordings; UNESCO certified; entry ₩1,100) and the viewpoint for Udo Island (우도 — the small island visible 3km offshore from Seongsan, known for peanut ice cream (땅콩아이스크림 — the island grows peanuts in the basalt soil and produces a distinctive peanut ice cream sold everywhere on the island)). Day 3 alternative: ferry to Udo Island (₩5,900 return, 15 min, from Seongsan ferry terminal).

Udo Island (우도 — ferry from Seongsan Port (성산포), 15 min, ₩5,900 return; the small island (6km × 3km) with 1,900 permanent residents and a very specific agricultural character (peanut cultivation (땅콩), the volcanic basalt soil producing a sweet, rich-tasting peanut that is processed into ice cream, halva, and peanut paste of a quality specific to this island)). The island has no cars for tourists — only rental electric bikes, mopeds, and horses (₩20,000–50,000/day); the 17km coastal circuit by electric bike is the standard Udo activity (3–4 hours, stopping at: Seobin Baeksa beach (the white coral sand beach, one of the only white coral beaches in South Korea — the sand is composed of crushed coral and shells, not quartz, giving it a dazzling white colour and an irregular coarse texture), Udo Lighthouse (the old 1906 lighthouse, the oldest in Jeju), and the eastern basalt cliff views)).

Hyeopjae Beach (협재해수욕장 — Hyeopjae-ri, Hanrim; west coast of Jeju Island, 35km from Jeju City; the most popular beach on Jeju: a 1km stretch of white sand (from crushed shell and quartz, with a slightly greenish tinge from the crushed olivine volcanic mineral mixed in), turquoise water (the shallow water (1–2m deep for the first 100m, the depth of the volcanic platform) turns a distinctive jade-turquoise colour similar to the Caribbean), and views of Biyangdo Island (비양도 — a small volcanic island 3km offshore with a visible cinder cone)); the water temperature (24–26°C in August, 18–20°C in October — swimmable from June–October). The beach can be crowded in July–August — arrive early (before 10:00) or visit in May–June.

Cheonjeyeon Falls (천제연폭포 — Jungmun, Seogwipo; 'Pond of the God of Heaven'; the most dramatic waterfall complex on Jeju Island (distinct from the more accessible Cheonjiyeon Falls near Seogwipo): a three-tier waterfall system where the water falls (25m, then 13m, then 22m in three successive drops) into a series of pools in a deep basalt gorge; the area is a UNESCO Biosphere Reserve component and has a resident population of Jeju waterfall blind gobies (Sicyopterus japonicus — a rare freshwater goby that climbs the waterfall using its pelvic fins as a suction cup to ascend the vertical basalt faces)). The approach path (600m through subtropical forest with the canopy almost closing overhead — ficus, Castanopsis, and tree ferns) is as atmospheric as the falls themselves. Entry ₩2,500.

Jeju haemul dolsot bibimbap (제주 해물돌솥비빔밥 — a Jeju-specific version of the Korean rice bowl dish (dolsot = stone pot (the hot stone pot creates a crispy scorched rice layer at the bottom (nurungji — 눌음지)), haemul = seafood): rice, abalone (jeonbok), sea cucumber (haesam), sea urchin roe (uni), and seaweed (michae — Jeju green laver), topped with gochujang (red chilli paste) and sesame oil, served in the stone pot still sizzling; ₩18,000–25,000). Jeju makgeolli (제주 막걸리 — the traditional rice wine of Jeju, 6–8% ABV, slightly fizzy and milky; the Jeju tangerine (hallabong) makgeolli version (₩8,000–12,000/bottle) has been developed since 2010 as a Jeju-specific product, combining the natural sweetness of the tangerine with the fermented rice base). The combination is the definitive final evening in Jeju.