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
Zuidwal volcano their surprise they hit volcanic rock beneath the reservoir rock, which turned out to be an extinct volcano. The gas field went in production in 1988 and is still producing gas. Another clue indicating the presence of the volcano was the temperature. While the usual temperature at that depth is about , they found . The volcano has a height of approximately and a circumference of several kilometers /miles. The volcano was formed about 160 million years ago, during a time of orogenesis on the European continent. The eruptions were short and severe with heavy explosions. This, along with the