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
Newberry Volcano magma chamber under the large, cauldron-like caldera at its summit. This caldera has dimensions of and formed about 75,000 years ago. Newberry Volcano first formed about 600,000 years ago, and has since been built up by several thousand eruptions. About 500,000 years ago, Mount Newberry attained an elevation of . Multiple eruptions created the caldera, but the main caldera-forming event occurred around 75,000 years ago from a major explosive eruption. It formed the crater lakes and Paulina Peak, which is the highest point on the volcano, at . As a result of its caldera-forming eruption, Newberry has a horizontal profile,