If there was a single place on the planet that best represents the scars of the frantic nuclear arms race during the second half of the 20th Century, it is the 18,000 km2 (6,950 sq mi) area located on the steppe in northeast Kazakhstan.
Known by either its quasi-Bond villain name the Polygon or as the Semipalatinsk Test Site, this was the primary nuclear testing zone for the Soviet Union over a period that straddled an extraordinary six decades.
A quite astonishing 456 nuclear tests took place at Semipalatinsk between 1949 and 1989, while the area remained active until the fall of the Soviet Union two years later. Quite simply, there is nowhere on earth that has been nuked as many times as Semipalatinsk.
As you’re watching this you’re probably already imagining an area far from any form of civilization, but sadly that was not the case. This testing site lay on the doorstep of numerous communities and Kazakh authorities have since estimated that 1.5 million people were exposed to nuclear fallout as the Soviet Union battled to keep pace with the United States.
Kurchatov City
Lying on the banks of the Irtysh River, in present-day Kazakhstan, Kurchatov is a small city with a painful and secretive past. Located in the northeast of the country, above Lake Blakash and just 400 kilometres (250 miles) from the Chinese border and even closer to the Russian frontier to the northeast, Kurchatov was, for many decades, a closed city. Nobody came in and nobody left without the express consent of the Soviet authorities. This was a city that did not appear on maps or any road signs in the region.
So what was so special about this small city with a population of just over 20,000? Absolutely nothing, but the vast area 64 km (40 miles) to the west, which is just a little smaller than the size of Wales, was quite a different matter. There is a bleak, barren beauty to the world here, but looks can be deceiving. This was once the epicentre of the most frenzied nuclear testing ever seen.
The USSR Emerges
As World War II drew to a close, the Soviet Union was in an awkward position. The nation had been allied with the U.S, Britain and France throughout the war, but its political ideology was always going to stand in opposition to western ideas of democracy.
With the USSR, or its satellite nations now stretching from the frozen coast on the Bering Strait to the Berlin Wall, a truly colossal power had emerged from the Second World War – and Joseph Stalin knew it. A superpower claim was in the offering, but the Soviet Union lacked one thing that the U.S held over it at the time – a nuclear weapon.
The Soviet Union had begun developing its own nuclear bomb during World War II under the Soviet atomic bomb project which was started in 1942, but by the time the U.S destroyed Hiroshima and then Nagasaki to kickstart the nuclear weapon’s age, the USSR was still some way off.
However, the events in the skies above Japan galvanised a much more intense effort by Soviet scientists and with a little help from both the German nuclear weapon project and the American Manhattan Project – done so with spies within the enormous U.S operation – the USSR was able to construct a nuclear bomb in record-breaking time.
The Testing Site

In 1947, Lavrentiy Beria, political head of the Soviet atomic bomb project was searching for a suitable site to test a weapon that was just a couple of years away. With such an enormous expanse of land at their disposal, it must have been difficult to narrow down a selection, but it is perhaps telling that the area chosen did not lie within traditional Russian territory.
The spot picked by Beria was a place that he brazenly described as “uninhabited”. The site where the bombs would eventually be tested was certainly free of human life but located just 120 kilometres (74.5 miles) from the city of Semipalatinsk, now Semey, with other towns and rural communities close by, it was a ludicrous claim. Either Beria was supremely stupid, or staggeringly indifferent. And considering what came next, I’d been willing to bet it was the latter.
Construction of the early test facilities within the Polygon was done so with the slave labour of the Gulag system, which saw an estimated 18 million people pass through it between the 1920s and 1960s. What is today Kurchatov City began life as a laboratory complex then known simply as the Semipalatinsk Test Site (STS) and later came to house those working on the nuclear tests and their families.
Along with laboratories and testing facilities built at the site, houses made of wood and bricks as well as bridges and a simulated metro railway were constructed within the Polygon area to test the destructive power of these new weapons. Military equipment, including tanks and aircraft, were also brought in to see how they would react. There was also a slightly evil Noah’s Ark aspect here because 1,500 animals were also relocated to the testing area – though there’s no record of what they were or what came of these animals – though let’s be really honest, it probably wasn’t pretty.
The Semipalatinsk Test Site was now ready, all it needed was a nuclear bomb.
Operation First Lightning
On 29th August 1949 at 7:00 a.m, the ground began to shake around the Polygon as the Soviet Union successfully detonated its first nuclear weapon, code-named RDS-1, or First Lightning by the Soviets, or Joe-1 by the Americans, in reference to Joseph Stalin. It came with a plutonium core that made RDS-1 similar to the Fat Man bomb that had been dropped on Nagasaki and had a blast yield of 22 kilotons of TNT.
As far as a nuclear weapon test goes, it was a great success, but one which the USSR was not ready to share with the world. Unfortunately for them, some United States Air Force WB-29 Superfortresses had been fitted with special filters to collect atmospheric radioactive debris, and a weather reconnaissance flight on the 3rd September between Misawa Air Base in Japan and Eielson Air Force Base in Alaska picked up radioactive particles. This was then cross-checked with other flights and the conclusion was clear – the Soviet Union had detonated its first nuclear weapon.
On 23rd September 1949, President Harry S. Truman announced publicly to the world what the Soviet Union had been hoping to keep under wraps and it acted as the spark to the nuclear arms race – the world was about to change dramatically.
Inside the Polygon
There is a lot that we don’t know about the Polygon area. Not only was it one of the most secretive places on the planet, after the dissolution of the Soviet Union, most of the files relating to events there were either destroyed or shipped back to Moscow without the newly independent Kazakhstan having time to see what the Soviet Union had already done to their land – I know, I’m surprised as you are.
More buildings and facilities were gradually added, including large tower blocks that were constructed in the middle of nowhere, purely to see how they would react to a nuclear blast, and vast tunnels built within the nearby Degelen Mountain, a complex that would eventually be used for underground testing.
It’s difficult to imagine what life must have been like for people living in the area with mushroom clouds frequently appearing on the horizon. People recall being knocked over by sudden shockwaves ripping through their communities and there are even stories of teachers in schools covering children in felt when they knew a detonation was planned – something they thought might protect them from whatever might be coming their way. But for most people, long term illness was not something that was given much consideration. This was still the early days of nuclear testing, and with information tightly controlled by Soviet authorities, almost all of what was going on remained entirely mysterious. This was not a place you asked questions or raised concerns.
But those exploding the nuclear bombs certainly knew. A research centre built in the area, named the Anti-Brucellosis Dispensary Number 4, was in theory constructed to examine infectious diseases found in cattle. However, the reality was far darker and the facility was instead said to focus on how radiation affected the human body. And what better place for that kind of research than inside the Polygon.
The horrifying reality of the Semipalatinsk Test Site was that this was not just a place to test how these weapons worked or how easily they could knock down a building, this was a test site with thousands of human guinea pigs where results were carefully logged. There is even the shocking story of the authorities sending a shepherd out on the steppe with his flock for five days after a detonation, simply to see how his body would react.
Testing, testing, testing
As I mentioned at the start of the video, this was the site of a staggering 456 nuclear tests, including 340 underground in boreholes or tunnels and 116 atmospheric explosions. In 1963, the Partial Test Ban Treaty came into effect which banned above-ground nuclear testing, as well as in space and underwater. The result meant that from 1963 onwards, almost all of the tests done at the Polygon were conducted underground, often within the Degelen Mountain Complex.
This must have come as a pleasant change for those living around the area who had grown sadly used to seeing mushroom clouds billowing up into the atmosphere. And when I say pleasant, I’m stretching the use of that word much further than it has any right to be used. Even after underground testing began, the effect it had on the local population was horrific – which we’ll come back to a little later in the video.
With so many tests, it’s difficult to pick out the most important, but let’s give it a go anyway. RDS-4 was tested on 23rd August 1953 and was a 1200 kg (2646 lb) device dropped from an IL-28 aircraft above the Polygon that had a blast yield of 28 kilotons. This design later went on to become the Soviet Union’s first mass-produced tactical nuclear weapon.
Another major milestone was the RDS-37, which was the Soviet Union’s first two-stage hydrogen bomb, first tested on 22nd November 1955 at the Polygon. This was a weapon that had had its yield purposely reduced with the hope of limiting the damage to the nearby area, but a shock wave was unexpectedly focused back downward because the weapon was initiated under an inversion layer, meaning a deviation from the normal change of atmospheric properties with altitude.
The enormous downward blast led to a trench filled with soldiers collapsing, killing one man inside. A building in the town nearby (now Kurchatov) also collapsed, killing a young girl. As many as 42 people in the town reported injuries from glass fragments as the blast shattered windows across the area.
The last detonation that we’ll look at was known as the Chagan Test, which was the first and largest of the 124 detonations in the Nuclear Explosions for the National Economy program that aimed to explore the use of nuclear explosions for peaceful means. That may sound like a ridiculous oxymoron but this was a period when very real consideration was being taken regarding how nuclear bombs could be utilized for large-scale earthmoving projects, in particular, to create dams, underground storage areas and for oil and gas exploration. And before you start thinking, what were those crazy Soviets up to, the Americans were doing exactly the same thing under Project Plowshare, in which 31 nuclear warheads were detonated in 27 separate tests.
The Chagan test, which took place at the Semipalatinsk Test Site on 15th January 1965, was an absolute monster and took months to prepare with tunnels dug beneath a dry bed of the Chagan River to effectively dam the river and create a lake. Which is exactly what happened. Now, remember this was after the Partial Test Ban Treaty which had banned atmospheric tests, but the Chagan Test was conducted at a relatively shallow depth that saw the explosion burst out of the ground and a mushroom cloud shoot skywards, taking with it around 20% of the bomb’s normal fission products into the atmosphere. The detonation was first detected in Japan and the U.S later made a formal complaint to the Soviets regarding the matter – which I assume somebody, somewhere simply scrunched into a ball and hurled into the bin because nothing ever came of it – although the Soviets did tone down their testing after that.
What has been left has come to be known as Chagan Lake – or by its more apt name Atomic Lake – measuring 400 metres (1300 feet) in diameter and 100 metres (328 feet) deep. Needless to say, this is not the place to cool off during Kazakhstan’s balmy summers as the water remains highly radioactive.
Closure & Clean Up
The final nuclear test in the Polygon came on 19 October 1989 as the ailing USSR staggered towards its final demise. With its dissolution in 1991, Russian officials removed what they could in terms of documents and warheads, but a staggering amount of waste remained, particular in the many tunnels and boreholes that had been created.
Newly independent Kazakhstan closed the area shortly after but this was not something that you can simply lock the doors and forget about. When people started breaking into the tunnels in the late 1990s, more to scavenge for scrap than attempting to get their hands on nuclear material, the Kazak government appealed to the United States for assistance. And so began a secret 17-year program involving Kazak, American and Russian scientists and engineers to clean up the Polygon, which involved tunnels being properly sealed and the pouring of special concrete into test holes to bind the waste plutonium.
The process was finally completed in 2012 at a final cost of $150 million (around $178 million today) and the area is slowly opening up for commercial activity, mainly mining, farming and tourism for the time being. But that’s not to say that this area is entirely safe, far from it. The Opytnoe Pole, where the first detonation took place in 1949, still shows levels of radiation that are 70 times higher than normal levels.
A Health Disaster
It may now be over thirty years since the last nuclear detonation at the Polygon, but the effects on those living nearby remain tragic. Even in the early years of testing, people in the vicinity had a suspicion that the increasing mystery illnesses that they were experiencing were a direct result of what was happening at the test site. But of course, this was not something anybody dared to question during the oppressive Soviet period.
All of the tests done within the Polygon equalled more than 2,500 Hiroshima bombs, and while direct effects from the explosions themselves were rare, the radioactive material carried by the wind was quite another story. There were numerous instances of mass cases, such as in August 1956, when after a test at the Polygon, more than 600 residents in the industrial city of Ust-Kamenogorsk, approximately 400 kilometres (248 miles) east of the test site, were admitted to hospital with radiation sickness. Of those, it’s unclear how many died.
But more often than not, this was a slow-burning horror that sometimes took years to fully reveal itself. Even today, children in the area are 50% more likely to have mutations in the minisatellite regions of their DNA than in other parts of the country, and while scientists are still unsure of what exactly this means, it appears it may increase the chances of developing cardiovascular diseases.
There are also significantly high rates of cancer, tumours, thyroid abnormalities, infertility, as well as physical abnormalities at birth. Depression and PTSD have also been painfully common in the communities around the site and when you think about what this area has been through, it’s not difficult to see why. The earth may have stopped shaking long ago, but the tremors are still very much felt close to the Polygon.
A Place of Horror
What took place within the Polygon for nearly six decades is a little difficult to really get your head around. Not because of the staggering number of nuclear tests, but the astonishing disregard for those living nearby. While health records taken by Soviet authorities at the time will probably remain locked away deep within the bowels of the Kremlin for eternity, you can’t escape the frankly horrifying prospect that they knew exactly what they were doing and the damage it would cause to hundreds of thousands of people.
Today, the most heavily nuked area on the planet is largely empty. There is a raw, almost foreboding beauty to the landscape but if you look closely you’ll see the scars of craters, strangely shaped mounds and half-destroyed buildings.
But the true horror of the Polygon is not so obvious and certainly not as visible. For those living in the area, many of whom were born after the worst of the testing, the disturbing legacy of the Semipalatinsk Test Site can be seen in their day to day lives as many continue to struggle under a dark cloud that refuses to dissipate, more than three decades after the Polygon was finally closed.