More than 40% of all the gold ever mined on Earth has come from South Africa's mines—and it's thought that zama-zamas mine about 10% of what the country annually produces each year. That's the name (it roughly translates to "take a chance") that's been given to the country's illegal miners, who typically hail from neighboring countries and who "go through hell" in their search for leftover gold in mines that were abandoned as the country's mining industry faltered in the 1990s. As Kimon de Greef writes in a lengthy piece for the New Yorker, "In no other country in the world does illegal mining take place inside such colossal industrial shafts," some more than a mile deep, that zama-zamas often climb down without ropes or using the most tenuous of support structures.
Accessing the underground tunnels is so hard that many don't leave for months or even years, trying to survive temperatures in excess of 100 degrees, insane humidity, no ventilation, and the threat of rockfalls and methane-related explosions. One doctor who has treated zama-zamas described gray skin and widespread tuberculosis. But in de Greef's view there is perhaps a bigger danger: the crime syndicates that run the mines and battle over turf. He writes that in Welkom, which has 50 mostly abandoned shafts, essentially the only way to get underground is to pay a protection fee to the gangs. One man described paying $1,000 for permission to enter, and double that to leave. After a year underground he didn't make enough money, so he went back. (Read the full story for much more, including how the operation to put an end to illegal mining in Welkom may have caused hundreds of zama-zamas to starve to death.)