Hallasan National Park (9.6 km), Seokgulam Trail (1.5 km), Gwaneumsa Trail (8.7 km), Donnaeko Trail (7 km), and Eoseungsaengak Trail (1.3 km). The longest trail is Seongpanak Trail which takes about 4.5 hours. Hallasan comprises 153.112 km of the Jeju Island. It rises 1.950 m above the sea level which means the highest mountain in South Korea. This mountain was formed in the fourth Cenozoic era by outburst of volcano. It is mostly composed of basalts. It is extending east and west, and it has high and gradual descent. On the other hand, the south part of the mountain is steep. In the
Jackson Volcano limestone. The structure was noticed by Hopkins in 1917 and a successful gas well was drilled in 1930, but the field was nearly exhausted by 1939. Jackson Volcano ash within the Eutaw Formation produces oil in the Tinsley Oil Field, where oil was first discovered in the Woodruff Sandstone (Selma Chalk), an eroded sand from Jackson. Jackson Volcano Jackson Volcano is an extinct volcano beneath the city of Jackson, Mississippi, under the Mississippi Coliseum. The uplifted terrain around the volcano forms the Jackson Dome, an area of dense rock clearly noticeable in local gravity measurements. E.W. Hilgard published his theory