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
Hallasan from the sea is formed on the coastal area and the peak temperature is mainly observed during the daytime. The change of the minimum temperature varies depending on the degree of cooling of Hallasan and the intensity of the wind speed.When the wind blows due to the predominance of sea breeze, the air cooled in Hallasan descends to the coastal area and induces the decrease in temperature. When the synoptic wind blows strongly, the cold air of Hallasan moves to the downwind side and the lowest temperature appears. The lowest temperature in the downwind area is 2 ~ 5℃ lower