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
Maitland Volcano volcanic activity created a complex edifice of trachyte and trachybasalt that formerly overlain the central part of the basaltic shield. Magmatism at Maitland continued until about 4.6 million years ago when the volcano went extinct. Volcanic activity at Maitland Volcano was consistent with extensional stresses across the northern Canadian Cordillera that began around 10 million years ago as a result of new plate motions between the Pacific and North American plates. This contributed to lithospheric thinning and decompression melting of OIB-like mantle to produce alkaline Neogene magmatism. The time span of 600,000 years for magmatism at Maitland Volcano is relatively