[1] It was inscribed as one of the UNESCO World Heritage Sites in 2007 because of the Geomunoreum Lava Tube System and the exhibition of diverse and accessible volcanic features which are considered to demonstrate a distinctive and valuable contribution to the understanding of global volcanism.

[3] A central feature of Jeju is Hallasan, the tallest mountain in South Korea and a dormant volcano, which rises 1,950 meters above sea level.

Volcanic activity on Jeju began approximately in the Cretaceous and lasted until the early Tertiary period.

Halla Nature Reserve is the Pillemot Cave, a site dating to the Paleolithic period.

Archaeological evidence from the cave suggests that people have occupied the island since the Paleolithic period.