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
Urartu local residents began to plunder the Toprakkale ruins, selling its artefacts to European collections. In the 1880s this site underwent a poorly executed excavation organised by Hormuzd Rassam on behalf of the British Museum. Almost nothing was properly documented. The first systematic collection of Urartian inscriptions, and thus the beginning of Urartology as a specialized field dates to the 1870s, with the campaign of Sir Archibald Henry Sayce. The German engineer Karl Sester, discoverer of Mount Nemrut, collected more inscriptions in 1890/1. Waldemar Belck visited the area in 1891, discovering the Rusa stele. A further expedition planned for 1893 was