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
Lake Nemrut which is in a not-eroded state. This unique structural geomorphology make it a subject of scientific research. About 450 plant species were recorded in and around Nemrut Caldera, around 200 (44%) of them belonging to the region. The diversity of the flora points out to the variation of climate conditions in the past. Around 38 (8.4%) of the existing plant species are endemic. The upside down tulip, which grows here, is a world-famous flower. The climax vegetation of Nemrut Caldera forms the haired birch ("Betula") and the trembling aspen ("Populus tremula"). Other notable plants growing around two lakes of the