South Korea most of which is not arable. Lowlands, located primarily in the west and southeast, make up only 30% of the total land area. About three thousand islands, mostly small and uninhabited, lie off the western and southern coasts of South Korea. Jeju-do is about off the southern coast of South Korea. It is the country's largest island, with an area of . Jeju is also the site of South Korea's highest point: Hallasan, an extinct volcano, reaches above sea level. The easternmost islands of South Korea include Ulleungdo and Liancourt Rocks (Dokdo/Takeshima), while Marado and Socotra Rock are the southernmost
Hallasan and study are needed to better understand the volcano. There is a crater lake on Hallasan called Baengnokdam (백록담/), literally "white deer lake." It is formed by the collapse of the top of the ridge by the movement of magma underground. There is a legend attributing the name of the lake to otherworldly men who descend from heaven to play with white deer. Depending on the season, the circumference of the lake is up to 2 kilometers with a depth up to about 100 meters. The configurative rocks of the eastern and western walls of Baengnokdam are different. The eastern