Cheju Island is a volcanic island, dominated by Halla-san (Halla Mountain): a volcano 1,950 meters high and the highest mountain in South Korea. The island was created entirely from volcanic eruptions approximately 2 million years ago, during the time period from the Tertiary to the beginning of the Quaternary period, and consists chiefly of basalt and lava. The eruptions took place in the Cenozoic era. It has a temperate climate, warmer than the rest of Korea, with four distinct seasons. Half of the summer is rainy, and the winter is fairly dry. There is a crater lake which is the only natural lake in South Korea.
There are many activites to do on this island such as: golf, horse riding, hunting, fishing, and mountain climbing. Depending on seasons, tourists can enjoy many festivals: penguin swimming contest in winter, cherry blossom festival in spring, midsummer night beach festival in summer, horse festival in autumn and many more.