Every time you post this photo to the WWI-related tags, god kills a
kitten young, idealistic poet.
This photo is from a volcanic island named Miyaki-jima, part of the Izu Islands, a small chain off the southeast cost of Japan. Miyaki-jima is home to the active volcano Mt. Oyama, and both visitors to and inhabitants of the island are required to always have a gas mask with them due to the danger of possible releases of sulfuric gas by the volcano. You are not required to wear the mask at all times, but, as you can see, it makes for some interesting photo-ops.