This snow tunnel near the Mutnovsky Volcano in Russia is almost a kilometre long. These tunnels form under the snow fields in deep ravines at the end of the summer thaw. Meltwater flows through glaciers towards lower elevations, finding an outlet at the terminus of the glacier and carving the ice on the way.
The photo of the snow tunnel was taken with three light sources: a torch, flash and natural light from the exit, holding for 2 seconds.
Photo credit: Michael Zelensky