Hallasan

Hallasan is the shield volcano that forms the heart of Jeju Island, and at 1,947 metres its summit is the highest point in South Korea. Locals say "Jeju is Hallasan and Hallasan is Jeju", and the mountain is visible from almost anywhere on the island. On top sits the crater lake Baengnokdam, and around 360 parasitic cones, called oreum in the Jeju language, dot its flanks. Most are cinder and scoria cones, and about 20 tuff rings formed by underwater eruptions lie near the coast and offshore.

An island built by a volcano

Jeju rose from the sea as basalt and trachyte lava piled up on the continental shelf. The summit crater is more than 400 metres across; Baengnokdam is explained as a pit crater, formed when the top collapsed as magma moved underground, rather than a vent built by erupting lava. The last eruption on record dates from 1007, noted in the Goryeosa chronicle, while geological evidence points to an eruption at least around 2,000 years ago; whether to class the volcano as active is still debated.

The area became a natural reserve in 1966 and a national park on 24 March 1970. In 2007 it was inscribed by UNESCO as part of the World Natural Heritage site "Jeju Volcanic Island and Lava Tubes". Old sources count it among Korea's three sacred mountains, together with Jirisan and Geumgangsan.

Long isolation from the mainland gave Hallasan a distinctive natural world. Vegetation changes in bands from subtropical plants near the coast to alpine species near the top, and more than 50 species found only on Jeju live mostly at high altitude. Some 121 bird species and around 4,300 insect species have been recorded, and ravens are a familiar sight on the trails.

What to see: five trails

• Seongpanak Trail (9.6 km): gentle but long, passing Jindallaebat shelter on the way to the summit's eastern rim.
• Gwaneumsa Trail (8.7 km): steeper, with a valley and the rock spire of Samgakbong. It is the other route to the summit.
• Yeongsil Trail (3.7 km): the shortest, along rocky ridges up to the Witse-oreum plateau.
• Eorimok Trail (4.7 km): through forest to the wide Witse-oreum plateau.
• Donnaeko Trail (9.1 km): a quiet route from Seogwipo in the south, reopened in 2009 after 15 years of closure.

The Yeongsil, Eorimok and Donnaeko trails stop at Witse-oreum and the Nambyeok junction below the summit. To see Baengnokdam you need the Seongpanak or Gwaneumsa trail.

Good to know

• Baengnokdam means "white deer lake"; legend says immortals came down from heaven to play with white deer here.
• The name Hallasan is traditionally explained as "a mountain high enough to pull down the Milky Way". It has also been called Buak, Wonsan and Yeongjusan, and older English sources call it Mount Auckland.
• The Hallasan Natural Reserve became Natural Monument No. 182 on 12 October 1966, and 19 of the mountain's bird species are protected as natural monuments.
• The peak is often wrapped in cloud, so clear views of the summit are rarer than you might expect.
• Depending on the season, Baengnokdam can reach about 2 km in circumference and up to about 100 metres deep. Its eastern wall is basalt and its western wall a trachyte lava dome, so the two sides are made of different rock.
• The routes from Yeongsil, Eorimok and Donnaeko to the summit have been closed since 1994 to let the vegetation recover.

Tripto tips

• Booking: to reach Baengnokdam via Seongpanak or Gwaneumsa you must book in advance through the Hallasan trail reservation system. Booking is free; check the current rules and monthly release dates on the booking site. Yeongsil, Eorimok and Donnaeko, which do not reach the summit, need no booking.
• Winter schedule (1 October 2026 – 31 March 2027): all trails open at 05:00. Last entry is 11:30 at Seongpanak and Gwaneumsa, 12:00 at Eorimok and Yeongsil and 10:00 at Donnaeko. Hikers must leave the eastern summit by 13:30 and the Jindallaebat and Samgakbong shelters by 15:30.
• Time needed: the Seongpanak round trip takes a full day. For a shorter hike, take Yeongsil up to Witse-oreum and back.
• Seasons: late-spring azaleas, autumn colours and snow scenes are the highlights. In winter, crampons and warm gear are essential.
• What to bring: the summit routes are long, so carry plenty of water and snacks. Ticks live in the undergrowth, so wear long clothing and stay on the trail.
• Safety: the weather up high can be completely different from the coast. Check the Hallasan National Park website for weather and trail closures before you set off. In August–September 2026 the Samgakbong–summit section of the Gwaneumsa Trail was closed for repairs.