In Indonesia's East Java province, the Ijen crater is filled with one of the largest sulphuric lakes on the planet.
Here, sulphur miners brave the hazadrous environment to extract blocks of pure sulphur using simple tools.
Sulphur, referred to in the Bible as "brimstone", is an essential element for all life on Earth. But its dirivatives, such as sulphur dioxide and sulphuric acid, can be very dangerous for the lungs and eyes and can cause very serious chemical burns.
In a single day, a miner in Ijen can haul up to 100kg (220lbs) of sulphur, earning an average of $6 per day.