24.06.2013 Cullinan Diamond Mine

In 1905, 12 metres below the surface of the Highveld just east of Pretoria, the world's largest diamond, a 3,105 carat chunk of pure diamond magnificence, was found. The fellow who originally found it handed it over to his manager, who didn't believe that it was in fact a real diamond and - as legend has it - threw it out the window. It was then picked up by the foreman and sat on a desk for the next three months. Finally it was brought to the attention of the mine owner, Mr Thomas Cullinan, who recognised it for what it was, the world's largest gem quality diamond - now sometimes called 'the Star of Africa'.

With South Africa still heavily under the influence of the British crown, Thomas Cullinan sold the diamond to the government in Johannesburg, who then gave it to King Edward VII. A fake diamond was sent to the UK by ship with a police escort, while (having much faith in the postal system of the day) the real diamond was mailed all the way to Europe. It then took Dutch diamond cutters eight months to cut and model it into nine massive diamonds, which now form part of the British crown jewels.

Thomas Cullinan

Replica of the Cullinan diamond and the gems it produced

Cullinan is still a working mine employing some 1,000 people. It digs up diamonds for jewellery (the $5 million diamond necklace which Burton gave to Liz Taylor came from here) as well as tiny 'industrial diamonds' used by people like NASA. Apparently they are also now going through the very first slag heaps to search for more industrial quality diamonds which may have been discarded.

The highlight of any surface visit (1.5hrs, 105 Rand p.p - you can book them here www.diamondtourscullinan.co.za/) is reaching the lookout point where you can gaze out across the one kilometre wide expanse of the open part of the mine, which is over 500 metres deep. On an underground tour (takes four hours and sounds kind of scary), they take you down over 800 metres into the earth (in the next few years they will dig down to over 1100 metres!) where there are over 700km of tunnels.

At the top edge of the hole is a petrol station (with red roof)

Helmets are necessary when visiting the Big Hole as you have to walk right under the huge conveyor belts which carry the tons of rock dug out of the mine to extract diamonds. The mine produces 4,500 carats of diamonds everyday which involves blasting 11,000 tons of kimberlite out of the earth. Due to the seriousness of the illegal diamond trade in Africa, if you try to take anything from here, even just a bit of kimberlite which you find on the floor, you can face six years in jail.

The rocks come up in the lifts on the left and the people go down in the cage on the right

The town of Cullinan itself is lovely and a much nicer small town than Parys in the Free State, which the guidebooks all seem to rave about (that said the area around Parys is very pretty). All the houses are built from local sandstone and along the main street leading towards the mine there are dozens of cute little shops, cafes and restaurants, which make a perfect place to relax after an absorbing historical tour.

How we got there: Cullinan is easy to find by car. Heading north on the N1, just as you pass Pretoria you will find the turn off to Cullinan. The journey takes about 1.5hrs tops.