Sitting in the Ring of Fire, a 40,000-kilometre trail of tectonic activity that surrounds the Pacific Basin, Indonesia is home to more than 150 volcanoes. One of these, Kawah Ijen, located in East Java, constantly belches out a valuable mineral - sulphur - and local men breathe toxic fumes and risk death in order to collect the solidified substance in return for a few dollars a day. Photographs by Jefri Aries

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