Miners carry a goats head for burial in the crater as part of an annual offering ceremony on the Ijen volcano on December 17, 2013 in Yogyakarta, Indonesia. The ritual is performed by the sulfur miners of Mount Ijen who slaughter a goat and then bury the head in the crater of mount Ijenn. The sacrifice is performed to ward off potential disasters for the next year. The Ijen crater rises to 2,386m, with a depth of over 175m, making it one of the world's largest craters. Sulphur mining is a major industry in the region, made possible by an active vent at the edge of a lake, but the work is not without risks as the acidity of the water in the crater is high enough to dissolve clothing and cause breathing problems. (Photo by Ulet Ifansasti/Getty Images)

A miner extracts sulphur from pipe at the flow crater during the offering ceremony. (Photo by Ulet Ifansasti/Getty Images)

A goat head is seen on December 17 as preparations are made for a burial in the crater as part of an annual offering ceremony on the Ijen volcano in Yogyakarta, Indonesia. (Photo by Ulet Ifansasti/Getty Images)

A sulfur miner carries a goat's head in a white bag as he climbs to bury the head in the crater. (Photo by Ulet Ifansasti/Getty Images)

Miners carry a goats' head for burial in the crater as part of the offering ceremony. (Photo by Ulet Ifansasti/Getty Images)

A miner uses a pole to extract sulphur from a pipe at the flow crater during the annual offering ceremony on the Ijen volcano. (Photo by Ulet Ifansasti/Getty Images)