Kawah Ijen: burning sulfur and blue flames

Kawah Ijen is a well known Volcano in east Java. In its summit crater lies an acid lake and on the shoreline of this lake degases many fumaroles. The fumaroles transport tones of sulfur from earth interior to its surface. The sulfur condenses close to the fumaroles and thick layers of the yellow mineral solidify in one part of the deep crater.  Every day hundreds of miners climbing down the crater and dig the sulfur. In two baskets they carry the minerals to a weight station, 3 km downhill.