The project was completed in 1960 and, by the time it closed in 2004, All That’s Interesting goes on, quantities of diamonds worth a total of $13 billion had been excavated there. It’s only right that the venture proved lucrative, too, as it was a painstaking process to build in such an inhospitable place.
The mine, per Unknown World, is 3,900 feet in diameter and around 1,200 meters deep, among the biggest mines of its kind on the planet. So large is this gaping chasm in eastern Russia that it really can be perilous to aircraft. According to When On Earth, its sheer size can have a devastating impact on the flow of air around it and its temperature. Reportedly, helicopters have been caused to dramatically lose altitude and crash into the mine by this effect, which had led to flights in its airspace being banned.
All That’s Interesting explains that the air within the mine is warmer than the bitter air outside it, resulting in a deadly vortex. The impact of this would depend on the size of the aircraft, but there have reportedly been several incidents. Research within the mine continues, and in 2010, Russian company AB Elise discussed ambitious plans to create a solar-powered city within the chasm.