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
Kell (volcano) valleys. Within the Prizrak caldera complex are at least three partially nested calderas, each about 3 to 5 km in diameter. Kell is the largest of several small stratovolcanoes, composed mainly of lava, in the innermost portion of the caldera. The caldera also contains lava domes. The innermost caldera is thought to date from the Late Pleistocene. The activity of the volcano appears to have ceased in post-glacial time; there is no evidence of recent volcanism or hydrothermal activity. Kell (volcano) Kell () is a small extinct Holocene stratovolcano. It is located just north of the Zheltovsky volcano, within the