Kromdraai Gold Mine
For more recent history of South Africa's Gold Rush era (as opposed to the ancient history of humanity you'll find in the Cradle of Humankind like Maropeng and the Sterkfontein Caves), tour the small but fascinating Kromdraai Gold Mine, one of the country's oldest mines begun in 1881. Frankly, it's a little spooky. You don a miner's helmet and wander into the mine's murky depths on one-hour guided tours. It's not a difficult walk, and if you're lucky, you'll see bats roosting.
