This is Bourke's Luck Potholes which can be found along the Panoramic route between Johannesburg and Kruger in South Africa.  The potholes mark the start of the Blyde River Canyon and was named after gold prospector Tom Burke who successfully predicted that the area would hold lots of gold but was not lucky enough to find any himself.  The potholes (not shown in this sphere) are created by whirlpools created when the Treur and Blyde rivers combined.  These whirlpools bored holes into the rocks creating what are now called the potholes.

This is worth a stop if you are driving the Panoramic route and I would plan at least 2 hours to wander around and take pictures, oh and bring your water proof hiking boots and be prepared to climb on the slippery rocks to get the best shots.  I took a total of 6 spheres at the potholes and a few regular pictures as well.

-erik

source: http://www.sabie.co.za/gallery/Bourkes%20Luck%20Potholes.html