In the far East of Java, Kawah Ijen.
This volcano is known for its large lake of sulfuric acid (the largest in the world), and for its sulfur miners. The principle of the extraction of sulfur is quite simple: smokes, at very high temperatures, are channelled in pipes to cool sufficiently to allow sulfur to condense. It then flows into puddles, perfectly pure, and then crystallizes while cooling.
Miners break large plates and transport them on their backs from the bottom of the crater to the foot of the volcano.
Each man carries two pairs of baskets per day. The weight of a pair of baskets varies from 60 Kg to 90 Kg, the stronger miners carry baskets weighing over 100 Kg (220Lbs)!
The work in the crater and the climb back up are done in toxic fumes from the volcano. Their only protection is a wet cloth held in their mouths to filter only a small part of the gas…
The 160 meters of elevation difference between the bottom of the crater and the summit is to be climbed over fallen rocks. Quite difficult with good walking shoes and a gas mask, imagine therefore with simple flip-flops, without gas protection, with 80 Kg on the back!
Once at the top, they must come down the 500 m of elevation difference of the steep slope.
This work is so exhausting that miners can work only every two days.
Sulfur is purchased approximately 50 cents a kilo... which makes them rich men!