The Big Hole which is also known by its other name, Kimberley Mine, in South Africa is the world’s largest hole which humans excavated. It was dug by 50.000 miners who were working in diamond mine after first diamonds were found there in 19th century. They found there amazing amount of diamonds, precisely, they have found 2720 kilograms of diamonds there.
The most amazing fact is that workers who worked there weren’t using any advanced tools or machines while thy were digging. The hole was dug between 1871 and 1914 when there weren’t any advanced machines for digging so, they literally dug this hole by hands using some very basic tools like picks and shovels. Using that basic tools workers managed to move amazing 22 million tons of soil.
The Big Hole is about 215 meters deep and 463 meters wide. After the mine was abandoned because it became too dangerous for miners to dig further, the mine was shut down. However, company De Beers Brothers who owned that mine continued with diamonds exploitation by underground mining.
After excavation was finished, this place started to fill with underground waters and, as you can see from photos, it looks now like a lake. Water took about 20% (40 meters) of the depth of whole hole.
Image Sources: Wikipedia.