During the excursion (3.5 km one way) to the crater of the Mutnovsky volcano, you will see turquoise glaciers, bubbling mud pots, a boiling river, exhaling fumarole sulfur dioxide gas. Fumaroles are sources of hot gases in the craters and on the slopes of volcanoes, through which gases dissolved in magma leave the earth's interior. As a rule, thick steam curls over large fumaroles, since the magma contains a large amount of water. In addition to water, carbon dioxide, various oxides of sulfur, hydrogen sulfide, ammonia and other chemical compounds are emitted through fumaroles. This is an absolutely amazing, but rather dangerous place - the path passes in the immediate vicinity of these volcanic emissions, powerful sulfur vapors and ammonia. Therefore, this is the most difficult place for tourists to pass one by one, accompanied by a guide, with extreme caution.