This working mine is where the world's largest ever diamond, the Cullinan Diamond (later to become Star of Africa) was discovered. Tours of the mine take in the engine rooms, shafts, diamond display rooms and the look out point where you can observe the massive hole (four times bigger and two times deeper than Kimberley's). Tours last 1.5-2hrs and there are plenty of good restaurants and a brewery nearby. Cullinan is around 45mins drive from Joburg via the M1 and R513.