Cullinan diamond mine tour: underground at the source of the world's largest diamond
The mine and the stone
The Premier Mine (now the Cullinan Mine, renamed 2003) was opened in 1902 by Sir Thomas Cullinan on the farm Elandsfontein, 30 km east of Pretoria. On 26 January 1905, superintendent Frederick Wells noticed a glint in the kimberlite wall of the mine at a depth of 5.5 metres. He dislodged a stone with his penknife. It was 3,106.75 carats — the largest rough diamond ever found.
The Cullinan Diamond was purchased by the Transvaal government and presented to King Edward VII in 1907. It was cut into 9 major stones and 96 minor stones by the Asscher Brothers of Amsterdam — Joseph Asscher reportedly studied the stone for 6 months before making the first cut, and fainted after doing so. The two largest pieces, the Great Star of Africa (Cullinan I, 530.2 carats) and the Lesser Star of Africa (Cullinan II, 317.4 carats), are set in the British Crown Jewels — the Sovereign’s Sceptre and the Imperial State Crown respectively.
This is the actual mine you are going underground in.
What the underground tour involves
The Cullinan Mine offers two tour types:
Surface tour (2 hours, approximately ZAR 150): covers the history of the mine, the surface plant (crushing, sorting, recovery), and includes visits to the surface excavations and the replica of the original Premier Mine headgear. No underground access.
Underground tour (2-2.5 hours, approximately ZAR 500-600): the significant experience. Involves:
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Safety briefing and equipment issue: hard hat, reflective vest, safety boots (provided if needed), and the basics of underground mine safety. The briefing is thorough — this is a working mine.
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The cage descent: the mining cage drops at approximately 9 metres per second. You descend to a working level 763 metres below surface. The cage is industrial mining equipment, not a tourist elevator.
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Underground access: you walk through active production tunnels (temporarily cleared of active blasting work for the tour period). The kimberlite pipe — the vertical geological formation of diamond-bearing rock — is visible in the tunnel walls. The difference in visual texture between the surrounding country rock and the kimberlite is immediately apparent.
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Production equipment: active drilling rigs, load-haul-dump vehicles (the machines that move the blasted rock to the ore passes), ore passes themselves (the shafts through which rock drops to the lower levels for processing). The guide explains what each element is doing in the current production cycle.
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Recovery area: the section where the kimberlite is processed to extract diamonds. The sorter — the mechanical and x-ray separation equipment — is the most technically sophisticated element.
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Return ascent: the cage back to the surface.
Physical requirements: there are no strict fitness requirements but claustrophobia is a real factor — the tunnels are working mining size (2-2.5 metres height), not tourist-size. If you are significantly claustrophobic, the surface tour is the appropriate choice. The tour involves walking approximately 2 km underground on uneven terrain. The temperature underground is approximately 18-22°C (warmer than surface in winter, cooler in summer).
Booking and logistics
Book direct: the Cullinan Mine tours must be booked in advance — walk-up admission is not available for the underground tour. Book online at cullinanmine.co.za or through the tour operators listed below.
Departure times: underground tours typically depart at 9:00am and 11:30am (check current schedule at booking). Tours run Monday-Saturday. Sunday access is limited.
Age restriction: minimum age for the underground tour is 10 years (with parental consent). Children under 10 can do the surface tour only.
What to wear: you will be issued a hard hat and reflective vest. Wear closed shoes (safety boots are available if you don’t have appropriate footwear). Old clothes you don’t mind getting dusty.
Photography underground: permitted in non-active areas. Flash photography near any electrical equipment is not permitted. Underground lighting is limited — bring a phone camera with a strong night mode.
For the mine + Pretoria full-day combination:
Cullinan diamond mine and Pretoria full-day tourFor the mine tour alone:
Cullinan diamond mine tour From Johannesburg: Cullinan diamond mine guided tourCullinan town and the additional context
The village of Cullinan (population approximately 5,000) was built by the mine company in the early 1900s to house mine management. It is a remarkably intact Victorian company town — the church, the mine manager’s house (Union Buildings-era architecture), the hotel, and the company store are all preserved and in use. The village has been declared a provincial heritage site.
The Premier Mine Pub and Restaurant in the original mine manager’s house serves lunch and is a pleasant stop before or after the tour.
The Cullinan Diamond Centre on Oak Avenue sells diamonds (primarily from the Cullinan Mine itself and from the De Beers sorting facility), set stones, and Cullinan-branded items. Prices for unset rough diamonds start at approximately ZAR 500-800 for small commercial-quality stones (not gem quality — the gem stones go directly to the cutting market). Gem-quality stones are significantly more expensive.
Combining Cullinan with Pretoria
Cullinan is 30 km east of Pretoria on the R513. The drive from Pretoria (Union Buildings area) is approximately 30-35 minutes. A natural combination:
9:00am — Cullinan underground tour (2.5 hours, back by 11:30am)
Noon — Lunch in Cullinan town (Premier Mine Pub)
1:30pm — Drive to Pretoria (30 minutes)
2:00pm — Union Buildings and Freedom Park (2.5 hours)
4:30pm — Drive back to Johannesburg or dinner in Pretoria
This is a manageable 8-hour day from a Johannesburg or Pretoria base.
From Johannesburg: Pretoria, Soweto and Apartheid Museum tourThe De Beers context
The Premier Mine has been majority-owned by De Beers since 1920 (De Beers acquired it following a diamond market crisis). De Beers was for most of the 20th century the world’s dominant diamond cartel — controlling supply from multiple mines across southern Africa and Namibia and suppressing prices by limiting the quantity of diamonds released to the market.
The cartel was broken in the early 2000s by the entry of Russian and Australian diamonds outside De Beers’ control. The company now operates as a joint venture between the Anglo American mining group and the Botswana government, which took a major stake in the 1970s as a condition of developing the Jwaneng and Orapa deposits.
Understanding this corporate history gives the Cullinan visit another dimension: the diamond in your hand is the product of a geological process 90 km underground, extracted by an industry with a specific and complicated political and economic history.
FAQ
What is the largest diamond ever found at Cullinan since 1905?
The Cullinan remains the largest single crystal ever found. In 2019, Petra Diamonds (which acquired the mine from De Beers in 2008) found a 424-carat high-quality blue diamond at Cullinan — the largest blue diamond ever found. It was sold for $50 million in September 2021.
How deep is the mine currently operating?
The active mining areas reach approximately 800-900 metres below surface. The ore body is estimated to continue to approximately 2,000 metres.
Is it possible to buy the actual rough diamonds recovered from the mine?
Commercial-grade rough stones (not gem quality) are occasionally available from the Cullinan Diamond Centre. Gem-quality rough from Cullinan goes directly to De Beers’ international sorting and selling operation in Gaborone, Botswana, and is not available to retail visitors.
How do I get from Johannesburg airport to Cullinan?
OR Tambo International Airport to Cullinan is approximately 60 km via the R21 and R513, about 45-55 minutes. Uber operates this route; a private transfer or rental car is the most practical option.
