World Natural Heritage Jeju Official Website
Mt. Hallasan is the central peak of the gently sloping shield volcano of Jeju Island. It is the highest mountain in South Korea, reaching 1,950 m above the sea level. Mt. Hallasan boasts peculiar volcanic landscape, produced by the crater lake Baeknokdam at the summit, the precipitous rocky cliffs of the Yeongsilgiam, and about 40 volcanic cones. Baeknokdam crater is exceptional in that the western half of that area is formed by trachyte lava, whereas the eastern half is made of basalt lava. It is assumed that the trachytic lava dome was produced first followed by the creation of the crater by basaltic volcanic activity. The mountain has been protected from human activity since 1970 and is renowned for its unique ecology and biodiversity in addition to volcanic geology and geomorphology.
Seongsan Ilchulbong Peak
Seongsan Ilchulbong is an archetypal tuff cone formed by hydrovolcanic eruptions upon a shallow seabed about five thousand years ago. The 180 m-high tuff cone, dominating the eastern seaboard of Jeju Island, not only preserves its bowl-like crater but also provides excellent sea-cliff exposures of diverse internal structures. These features have great geologic value in that they provide a basis for interpreting the eruptive and depositional processes of hydromagmatic volcanoes worldwide in addition to the past volcanic activity of this tuff cone.
Geomunoreum Lava Tube System
There are about 360 oreums (volcanic cones) scattered throughout Jeju island. Of those, the lava tube system of Geomunoreum alone was designated as a UNESCO World Natural Heritage under the title of Geomunoreum Lava Tube System. Why was it selected among all the others? The answer lies in the mystical beauty of Geomunoreum’s Lava Tube System created by molten lava streams that flowed north-northeast towards the sea 14km away.
Lava seeped upward from Geomu noreum, of Seonheulri to the east of Mt. Hallasan, and flowed on the ground to create large-scale lava tube systems including Bengdwigul Lava Tube, Manjanggul Lava Tube, Gimnyeonggul Lava Tube, Yongcheondoggul Lava Tube, and Dangcheomuldonggul Lava Tube.