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
Wonchi (volcano) Wonchi (volcano) Wonchi is a volcano located west of Addis Ababa, Ethiopia. At above sea level, it is the highest volcano in Ethiopia, from Mount Dendi, Ethiopia's second highest volcano. Wonchi is located at equal distance between the towns of Ambo and Woliso. The volcano has a wide caldera, and a single crater lake, Wonchi lake, about below the rim of the volcano. Study of Wonchi's caldera is incomplete; initial findings show it could be as much as deep, and the lake itself could be as deep as . Besides Wonchi lake, the caldera also contains hot springs, waterfalls, valleys,