Kawah Ijen and the blue fire

Sulfuric gas comes out of cracks on this East Java volcano at up to 600 C and ignites, and because it burns in the dark it burns blue, in sheets that can reach five metres. It is the largest blue flame area in the world and people hike up at two in the morning to see it. In the crater sits the largest highly acidic lake on Earth, a kilometre across, measured below pH 0.3 in 2001 and at 0.13 in the middle in 2008, which is battery acid. And working in it, in the fumes, are about 200 miners who break out roughly 14 tonnes of sulfur a day and carry it out in baskets of 75 to 90 kilos, up the crater wall and then three kilometres downhill, for around thirteen dollars. Most work without respirators. Look at the fire, and then look at what it costs the people who work there.