Kawah Ijen is one of the most incredible and surreal places I've ever visited. It's the site of a labor intensive sulfur mining operation where miners collect and carry huge loads of pure sulfur up from the crater floor along a steep, rocky path amid clouds of sulfur dioxide gas, all for the equivalent of about ten dollars a day. It is also home to the largest lake of sulfuric acid in the world. I wanted to explore this volcano in the most extreme manner I could think of... By taking a small boat out onto the acid lake. The ph of the lake water is 0.5, similar to the strength of car battery acid.