Today engineers use machines of many kinds to dig holes for oil and to lengthen tunnels inside mines.
But before the invention of these machines, man had to use his own hands along with a pick and shovel to dig holes in the ground. The deepest hole in the world of this kind was a diamond mine in Kimberley, South Africa.
This well was 240 m deep and was about 460 m in diameter, and it took 43 years to make it. The workers started the hole in 1871, and it wasn't finished until 1914.
The amount of soil removed when digging the hole was more than 28 million tonnes. But only three tons of diamonds were obtained from all that land!
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