Hallasan Mountain (한라산)

Hallasan is the highest mountain in South Korea, rising 1,950 meters at the center of Jeju Island and inscribed as a UNESCO World Heritage Natural Site as part of the Jeju Volcanic Island and Lava Tubes designation. Geologically, Hallasan is a shield volcano with a summit caldera (Baengnokdam Lake — "White Deer Lake" — typically holding water seasonally) at the top, formed by long volcanic activity that built up Jeju Island itself. Multiple marked hiking trails climb the mountain from different starting points (Seongpanak, Gwaneumsa, Eorimok, Yeongsil), with summit-access trails restricted to two routes (Seongpanak and Gwaneumsa) and shorter ridge trails for those who prefer not to climb to the summit. Day-trip hiking is the standard pattern; the mountain is best in spring azalea, autumn color, or stable-weather summer windows.