Volcanoes have long been considered one of the most large-scale natural disasters because on the one hand, and on the other - for the same reason - have attracted the attention of geologists and the best-known journalists in the world. And we tried to rank the most dangerous volcanoes in the world. Volcanoes tend to concentrate in certain areas, like flocks of birds. For example, in the Pacific, to be exact, Indonesia. Also, there is a huge concentration of volcanoes in the Mediterranean. Here we have focused on the most dangerous volcanoes. While, however, the fear for such a threat to humanity is rather strange: towns and even cities are built around many active volcanoes. Thus, Ulawun or Ulavun is considered one of the most dangerous volcanoes of the planet. Ulawun is an active volcano, located on the island of New Guinea, Papua New Guinea, about 130 km south-west of Rabaul. The height of the volcano is of 2334 m above the sea level. This is one of the most frequently erupting volcanoes in the world. First, the volcano was visible above the water and causes severe tsunami, erupting under the water. But in 1878 it went under the pressure of the faults in the crust, and then an aerial eruption began. One of the most dangerous eruptions took place on 28 May 1937, when the capital was literally covered with ashes. Since the beginning of the XVIII century 22 volcanic eruptions occurred. The last eruption occurred in 2007. Ulawun is one of the most frequently erupting volcanoes in the world.