Nemrut (volcano) of the earliest trade routes. Two eruptions of Nemrut were probably witnessed by people of Urartu, an ancient state located in the eastern Turkey. These eruptions occurred c. 787 BC (period of King Menua) and c. 657 BC (period of King Rusa II), and the latter eruption might cause the sudden disappearance of the city Uaiais located 30 km east of Süphan. In the 1980s, Japanese volcanologists studied the evolution of gases inside the caldera of Nemrut. They found that the ratio of helium isotopes He/He is 1.06, which indicates volcanic activity (most of the measured helium evolved from the
Mount Kumgang Mount Kumgang Mount Kumgang () or the Kumgang Mountains are a mountain/mountain range, with a Birobong peak, in Kangwon-do, North Korea. It is about from the South Korean city of Sokcho in Gangwon-do. It is one of the best-known mountains in North Korea. It is located on the east coast of the country, in Mount Kumgang Tourist Region, formerly part of Kangwŏn Province (). Mount Kumgang is part of the Taebaek mountain range which runs along the east of the Korean Peninsula. Mount Kumgang has been known for its scenic beauty since ancient times and is the subject of many