Mirny Diamond Mine: Russia’s Terrifying 525-Meter Hole Where Helicopters Are Banned From Flying
There is a hole in Siberia so vast that it generates its own downward air currents — strong enough that helicopters are officially banned from flying over it. So deep that the trucks that once worked at its bottom appeared from the rim as tiny dots. So wide that the road spiraling down to those trucks was 8 kilometers long just to manage the gradient.
The Mirny diamond mine is 525 meters deep and 1.25 kilometers wide. For 44 years it was one of the most productive diamond mines ever operated — producing billions of dollars worth of stones for the Soviet Union. It included some of the largest gem-quality diamonds ever found anywhere on earth.
And then in 2004, it was largely abandoned.
How the Mirny Diamond Mine Was Discovered
The Soviet Diamond Search
The Mirny mine was discovered in 1955 by Soviet geologists conducting a systematic search for diamond deposits across Siberia — driven by the Soviet Union’s need for industrial diamonds for its manufacturing and military programs. When geologist Yuri Khabardin sent his famous telegram back to Moscow — “I am smoking the pipe of peace on top of a vast deposit of diamonds” — it triggered one of the most ambitious mining projects in human history.
Mining the Impossible
The mine was located near the town of Mirny in the Sakha Republic — in conditions of extraordinary difficulty. Winter temperatures regularly fell to minus 60 degrees Celsius. The ground was permafrost — frozen so hard that conventional drilling was useless. Jet engines were used to thaw the ground before excavation could begin. Special vehicles had to be designed. Workers operated in conditions that would have been considered impossible by normal engineering standards.
But the diamonds were extraordinary. In its peak years the Mirny mine produced over 10 million carats annually. A 342.5-carat stone named the Sputnik was among its most celebrated finds. The mine essentially funded a significant portion of the Soviet Union’s diamond export economy for decades. According to Wikipedia’s article on the Mirny mine, it is one of the largest excavated holes in the world.
Why Helicopters Are Banned Over the Mirny Mine
The Mirny diamond mine is so large and so deep that it creates significant downward air currents above the pit. The thermal dynamics of the enormous open hole — combined with wind patterns across the flat Siberian landscape — generate suction strong enough to pose a genuine danger to helicopters and small aircraft flying directly over it.
Russian aviation authorities officially banned helicopter flights over the Mirny pit during its operational years. This remains one of the most striking facts about the mine — a hole so large it controls the air above it.
The Mirny Mine Today — What Happened After Abandonment
Open-pit mining at Mirny ceased in 2004 when the pit became too deep to extract ore economically. Underground operations continue today through tunnels beneath the original pit floor. The open pit itself sits largely dormant.
Various proposals have been made for the future of the pit itself — including a genuinely extraordinary concept to cover it with a transparent dome and build a self-contained city inside, using the mine’s thermal properties to regulate the internal climate. Whether this extraordinary vision will ever be realized is another question entirely.
For now the Mirny pit sits in the Siberian wilderness — a monument to what human beings can extract from the earth when they want something badly enough.
Frequently Asked Questions About the Mirny Diamond Mine
Where is the Mirny diamond mine?
The Mirny diamond mine is located near the town of Mirny in the Sakha Republic of Russia, in eastern Siberia.
Is the Mirny mine still active?
Open-pit mining ceased in 2004. Underground mining operations continue beneath the original pit, but the famous open pit itself is no longer actively mined.
How deep is the Mirny mine?
The Mirny open pit mine is 525 meters deep — the equivalent of roughly 1,700 feet or about the height of the Empire State Building.
Why are helicopters banned over the Mirny mine?
The enormous depth and width of the Mirny pit creates powerful downward air currents above it. These are strong enough to be dangerous to helicopters and small aircraft, leading to an official flight ban over the pit.
Read more about extraordinary abandoned industrial sites — including our story about [the Detroit Packard Plant], America’s largest abandoned factory.