14th March 2007
The world's biggest country, Russia, has the world's biggest hole.
It began life as a fox hole in a remote ravine. But after an eagle-eyed geologist spotted its potential as a diamond mine, it grew and grew... and grew.
Today, 50 years after its discovery, the Mir Diamond Pipe in eastern Siberia is the biggest man-made hole in the world.
It plunges 574 yards into the frozen earth and its vast mouth has a diameter of almost one mile, making it clearly visible from Space.
The 220-ton rock-hauling trucks that labour down the spiralling road to its bottom take two hours to travel back up to its lip and look like matchbox toys against the gargantuan rock face.
The mine — known in Russian as a trubka — is now largely disused since its official closure in April 2004, but its legend lives on.
The herders and fishermen turned miners, who struggled to survive winter temperatures of -60c and short, insect-infested summers, say that when God made the world, his hand stopped as it passed over the area, spilling treasures across this frozen wilderness, 5,000 miles east of Moscow.
At its peak, the Mir mine produced on average 2 million carats of rough diamonds a year, worth at least £20million, and with nearby mines was responsible for 23 per cent of the world's rough diamonds.
The largest ones were the size of golf balls, including the 130.85 carat Olonkho diamond, worth about £250,000.
The town of Mirny, which clings precariously to the rim of the mine, was settled by prospectors in 1955.
That spring, a young geologist came across a fox hole in a ravine which had tell-tale blue earth. He had discovered a "pipe" — an area where a volcanic surge has brought to the surface a layer of bluish rock, called kimberlite, which plays host to diamonds.
When his news was relayed back to Moscow, the digging began. Jet engines were used to blast holes in the permafrost and dynamite was used to excavate the surface rock and loosen the kimberlite ore.
Once at the surface, the ore is crushed so that the diamonds can be picked out, cleaned with acid and sorted by hand.
Today, Mirny is visited by few outsiders thanks to a combination of red tape and appalling weather conditions.
The hole in the Earth's crust is so vast that it creates a vortex, which is said to suck helicopters and small aircraft into its maw.
No one knows what will become of this astonishing feat of engineering. Some call it a scar on the environment, but others appear in awe of the hole that produced such extraordinary bounty.