This is the old pit mine in Cullinan where they used to mine for diamonds, this is one of the biggest open pit mines in South Africa and while it is no longer active they are still mining for diamonds under the ground.

Cullinan is a small town located about 30KM east of Pretoria and was named after Sir Thomas Cullinan who bought the land in 1902 to begin mining for diamonds. The diamond mine in Cullinan has produced several famous diamonds including the Cullinan Diamond in June of 1905, the Cullinan Diamond is the largest in the world at 3,106 carats. (http://en.wikipedia.org/wiki/Cullinan,_Gauteng)

Cullinan is now a popular tourism destination for both locals and visiters who want to tour the mine, tour the local township (populated almost completely with workers from the mines), eat in one of the restaurants, or shop for a bit of diamond jewellery.