To stand on the slopes of Kawah Ijen is to be surrounded by beauty. The lake in the volcano crater is a stunning turquoise green, and the surrounding landscape strikes you with its views across the sea. White plumes of what appears to be steam billow from vents in the rock, adding to the ethereal atmosphere of the place. But looks can be deceptive. What seems like a tranquil pool is actually a 182 meters (597 ft) basin of sulfuric acid, and the clouds wafting above a toxic mix of sulfurous fumes. Despite its sublime beauty, this volcanic caldera is a place of fire and brimstone, as enchanting as it is deadly. No one knows this better than the men who come here daily to mine the toxic sulfur for which the volcano is famous.
Located in the East Java province of Indonesia, the Ijen volcano is part of a group of stratovolcanoes — volcanoes made up alternating layers of hardened lava, rock and ash. The caldera known as Kawah Ijen was formed about 3,500 years ago when three massive eruptions caused an area of about 25 kilometers (15.5 miles) to collapse into the volcano, creating the giant water-filled depression we see today. When the molten sulfur first emerges from the pipes it has a temperature of over 200°C (392°F) and is a deep, blood red color. As the sulfur cools down it begins to solidify into vivid yellow lumps. These lumps are what the miners then break down into manageable pieces, which they can transport down the volcano in wicker baskets. The miners produce about 14 tons of sulfur a day, which is used in the manufacture of a variety of everyday items, including cosmetics, fertilizer and even wine. It is also an important ingredient in the sugar refinery process.