Kawah Ijen is an active volcano in Indonesia that is mined for sulfur. Miners scale 2,600 meters to the crater, then down to the shore of a 200-meter-deep crater lake of sulfuric acid, where they retrieve heavy chunks of pure sulfur to carry back to a weighing station. They do all this without any protective masks or gear.
Mariana Trench is currently the deepest known point on earth. With its crushing pressures and pitch black waters, it is deeper than average cruising altitude of commercial airliners and harbors some of the strangest life form known to men.