Gorely Volcano
The active volcano

Gorely Volcano (1845 m / 6053 ft) is a newly formed giant in the caldera of an ancient destroyed volcano. It contains eleven craters. Prior to the eruption of 1986 nine of them were filled with lakes. After it there are only two left. In the process of outburst of 2010, the terrain changed again. One of the craters is still filled with a lake of meltdown water from glaciers and snowfields. The level of water in the second lake constantly changes and unstable. Due to the fumarole exits the water in the lake is full of acid. Because of fumarole vents the water in the lake is saturated with acids.

Here is an article about two pals who decided to spend a night in the crater of the erupting Gorely Volcano. «Kamchadal Style Rest. Overnight in the Crater of Erupting Volcano».