Jeju Island holds South Korea’s first natural UNESCO World Heritage inscription, awarded in 2007 for three volcanic components: the shield volcano Hallasan with its crater lake and 360 parasitic cones, the Geomunoreum Lava Tube System including the rare lava tubes where carbonate stalactites have formed on basalt walls, and Seongsan Ilchulbong, a tuff cone created 5,000 years ago whose crater has never filled with lava. The surrounding waters are still dived by the Jeju haenyeo, women free-divers whose tradition UNESCO listed on the Intangible Heritage register in 2016.