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
Roccamonfina (volcano) with an explosive eruption, including eruptions from the former caldera. This phase continued until some 285,000 years ago. The formation of the volcano also modified the course of the Garigliano and Volturno rivers. The Volturno moved southwest in what is its current course; the Garigliano no longer reached the sea, and formed a lake (Lake Lirino) until (around 200,000 years ago) it eroded rocks near Suio and assumed the current course. Roccamonfina (volcano) The Volcano of Roccamonfina is an extinct volcano in Roccamonfina, Campania, southern Italy. It was active from some 650,000 to 50,000 years ago. It comprises an isolated