Geomunoreum Lava Tube System

The Geomunoreum Lava Tube System is located between Seonheul-ri, Jocheon-eup and Weoljeong-ri, Gujwa-eup, Jeju City, Jeju Province, South Korea. This lava tube system refers to a series of lava tubes formed by multiple ancient eruptions of basaltic lava flow from the Geomunoreum volcano (elevation 456 m). The flows followed a north-northeast direction for about 13 km, going down to the coastline. It is estimated that the tube system formed between about 100 and 300 thousand years ago.