Underground Cities And 'Ghost' Miners: What Some People Do For Gold
South Africa's Mponeng gold mine is a 2.5-mile-deep network of chutes and tunnels that employs about 4,000 miners. Of course, that number doesn't include the miners who wander its tunnels clandestinely, stealing and refining ore. In a new book, journalist Matthew Hart investigates why gold and crime sometimes go hand in hand.