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
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,