Jeju Island (Jeju language: 제주섬, Korean: 제주도 Jeju do) is the main island of Jeju Special Self-Governing Province in South Korea, located southwest of the Korean Peninsula, in the southern waters of the peninsula between the East China Sea and the Yellow Sea. It has a population of approximately 670,000 and an area of 1,848 square kilometres, making it the largest island and tourist destination in South Korea. Jeju Island is a volcanic island formed by numerous continental shelf volcanic activities starting from the end of the Tertiary period, featuring a unique volcanic geological landscape. Jeju Volcanic Island and Lava Tubes were designated a UNESCO World Natural Heritage site in 2007. Major attractions include Hallasan Mountain, Seongsan Ilchulbong Peak, and Udo Island, each with its own unique charm and scenery.