registered Jeju Volcanic Island and Lava Tubes as the first Korean World Natural Heritage in 2007.
The crater of Geomun Oreum is 4,551m in circumference and 108m in depth. Its depth is similar to that of Sangumburi but with twice larger circumference. Within the crater, ‘Seonheulgot (Gotjawal)’ was created. Gotjawal (a Jeju dialect referring to an unmanned and unapproachable forest) is a naturally formed forest located on the middle slopes of Mount Halla, mixed with trees and vines entangled in where lava flowed in. So it is called the lung of Jeju Island, and Seonheulgot of Geomun Oreum also has a thick forest like a tropical rain forest