This Russian lake may seem inconspicuous, but you certainly wouldn’t visit it for a day out.

You’ve been trekking through Russia’s Ural Mountains, and you’ve just stumbled across something curious. It seems that you’re staring down upon a lake. But instead of clear-looking water, there’s a discolored appearance about it. Then you start to feel dizzy. It might be time to back away. Fast.

This basin is called Lake Karachay, and it’s not exactly a place that you should be lingering around. It’s a beautiful place, for sure, with a calm and serene atmosphere that might even be relaxing. But there’s a chance that simply standing there could quickly lead to your demise.

Lake Karachay is found in Russia’s west-central territory, specifically in a province known as Chelyabinsk. The area is perhaps most defined by the Urals, a mountain range with a degree of geographical significance. To put it simply, these mountains are considered to represent a physical border that separates Asia from Europe.

Karachay has broadly been known about for a few centuries, but it’s had something of a confusing history. Why? At various points, the water feeding the basin has diminished to such an extent that the lake’s been entirely dry. Given that, maps have sometimes shown the lake and at other times have not.

But it was right in the middle of the 20th century that the course of Karachay’s history took a particularly dark turn. At that time, the lake was recognized as a useful site for people conducting secretive activities. And from that point on, the place morphed into one of the most dangerous places on Earth.

That’s quite a statement, especially when we consider how perilous other lakes around the world can be. Let’s take Lake Natron, for example, which is found in the north of Tanzania. Natron is defined as a salt lake, which basically means that water surges into it but not out. Instead, it evaporates.

At a glance, we might say that Natron is a peaceful and beautiful landform. But that ultimately doesn’t take into consideration the specific nature of its water, which is extremely alkaline. It has a pH level of up to 10.5, in fact, which means that it’d be able to corrode skin. Ouch!

The water possesses this alkaline level owing to minerals that have been swept up from nearby hills. Sodium carbonate plays a particularly important role, a compound that was once utilized by the ancient Egyptians during the mummification process. Any creatures, in fact, unfortunate enough to find themselves in Lake Natron will find their bodies preserved as a result.

And these creatures are a striking sight. Though the science behind it is simple enough, the manner in which they’ve been frozen in place almost looks like the stuff of magic. It’s as if they were engulfed by the waters of the lake and immediately transformed into stone.

Nick Brandt can count himself lucky to have gazed upon the lake and its “stone creatures” with his own eyes. Because he’s a photographer who’s snapped some astounding pictures of the dead animals. And back in 2013 Brandt spoke with Smithsonian Magazine about Natron, saying, “When I saw those creatures for the first time alongside the lake, I was completely blown away.”

Not many animals call the waters of Natron home, as the conditions there are just too extreme. It seems that only one sort of fish can be found there, in fact, a species known as Alcolapia latilabris. But algae does grow in the lake, and flamingoes fly into the area to feast upon it.

Image: Thomas Kraft, Kufstein Tomkraft/CC BY-SA 3.0

But if so few animals live in the area, why are so many stone-like dead birds found there? Well, Brandt suspects that it has something to do with the chemicals in the lake creating a reflective effect. This tricks birds into flying into the water, but crashing onto the hard liquid-surface, killing them. The water level then diminishes during the drier times of year. And once this happens, the calcified carcasses appear on the shore.

Brandt elaborated to Smithsonian about the things he saw along the edge of the lake. “It was amazing,” the photographer recalled to the publication. “I saw entire flocks of dead birds all washed ashore together, lemming-like. You’d literally get, say, a hundred finches washed ashore in a 50-yard stretch.”

Of course, the animals weren’t exactly ready for being photographed right away. And as you can guess, Brandt took advantage of artistic license to achieve his pictures. After he’d found them along the shore, he then positioned them in “living stances.” This provided the images with a creepy, mystical feel.

Brandt presumably took great care in collecting his animals from the lake. Because the alkaline waters there are, by his own admission, dangerous. As he explained to Smithsonian, “It’s so caustic, that even if you’ve got the tiniest cut, it’s very painful. Nobody would ever swim in this – it’d be complete madness.”

Image: Joseph Thomas Photography/Getty Images

Natron is far from the only lake in the world that’s considered to be dangerous because of its natural characteristics. In Dominica, for instance, there’s a mountain in the Morne Trois Pitons National Park. At the top of this bluff, the appropriately named Boiling Lake can be found bubbling away.

And it’s not an exaggeration to call this place Boiling Lake. The waters there are boiling, and so going for a dip isn’t a good idea. At the very least, your skin will end up getting scalded and burnt. In the worst case scenario, it will lead to your demise.

Just looking at the lake should be enough to tell you that swimming in it is a bad idea. Clouds of vapor rise from the water, a sure sign that diving in is totally unwise. But also the water itself is as rough and chaotic as boiling water always is. You really shouldn’t need any more warnings.

But what’s actually causing this lake to bubble and steam? Well, the answer is pretty straightforward, even though such a phenomenon is really unusual. The body of water is directly linked to the hot, liquid rock that flows beneath the planet’s surface. And a series of vents allow gases to travel upwards to the lake.

Yet the water level of Boiling Lake has been known to fluctuate as has its temperature. Sometimes, apparently, the water can cool down to a tolerable level for people to swim in. But this should always be avoided. After all, even if the temperatures are bearable, the gases of the lake could still be really harmful.

Image: Joseph Thomas Photography/Getty Images

So Boiling Lake is a perilous place for living things, just like Lake Natron in Tanzania. But there’s another lake that should be avoided at all costs, even more so than these two landforms. We’re talking, of course, about Russia’s Lake Karachay. This place could be the most dangerous basin on Earth. And when we consider its history, it’s not hard to see why.

Image: Carl Anderson, US Army Corps of Engineers

Lake Karachay has the ill fortune of being situated close to a facility that isn’t exactly the safest place in the world. The Mayak Production Association, as it’s known, actually produces nuclear material. Because of that, the existence of the place was obscured for a long time. It was only in 1990 that the state – which was then the Soviet Union – admitted to it.

Image: Carl Anderson, US Army Corps of Engineers

For several decades before this admission, the Mayak site witnessed a variety of incidents that contaminated its surrounding environment. Nuclear meltdowns weren’t unheard of, and plenty of dangerous waste had been inappropriately deposited. As a result, people living in the area were increasingly stricken with illness and their babies were born with defects.

Image: Ecodefense, Heinrich Boell Stiftung Russia, Alla Slapovskaya, Alisa Nikulina

A river in the area known as the Techa became particularly polluted by the nuclear materials. This led a huge number of people to become stricken with radiation sickness. But because the activities of the Mayak site were being kept under wraps, doctors could only diagnose people with so-called “special disease.” Unbelievable!

Back in 1990 a publication called Nuclear Monitor printed an article about the Mayak Production Association facility. The piece was based on the observations of a number of American specialists who were permitted to visit the site. And they claimed that radioactive contamination in the areas surrounding Mayak was “astronomically” high. Plus their conclusions were supported by Soviet experts, too.

Image: Ecodefense, Heinrich Boell Stiftung Russia, Alla Slapovskaya, Alisa Nikulina

The authors of the article sought to compare the Mayak site against an equivalent facility in the United States. They first of all acknowledged that certain American weapon production plants are themselves damaging to their surroundings. But ultimately the extent of the damage caused by Mayak far outdid the American sites.

Image: Carl Anderson, US Army Corps of Engineers

According to the report’s authors, the radioactive contamination of the area’s Techa River was particularly significant. They claimed that over a seven-year period beginning in 1949, some 25 billion gallons of radioactive fluid was poured into the waterway. And there’s even evidence suggesting that some of this material traveled for 1,000 miles into the Arctic Ocean.

Image: Ecodefense, Heinrich Boell Stiftung Russia, Alla Slapovskaya, Alisa Nikulina

And on top of everything else, the area was further contaminated because of a nuclear incident in 1957. In September that year, a blast occurred at Mayak, ultimately tarnishing the environment with nuclear fallout. So it’s not surprising that people are no longer allowed to get close to the Techa River.

Image: Charissa Van Straalen/EyeEm/Getty Images

Taking a step back to 1951, a decision had been taken to stop dumping radioactive waste into the Techa. This was hardly a cause for celebration, however, as the lethal materials were merely diverted elsewhere. Now they were sent to Lake Karachay, which was also located in the vicinity. And it wasn’t long before these hazardous materials spread to other nearby places.

The extent of Karachay’s contamination was immense. In fact, a Soviet journal called Priroda went as far as to describe the lake as “the most polluted spot on the planet.” It was even suggested that merely standing along the lake’s edge would’ve been enough to kill you within 60 minutes.

Image: Ecodefense, Heinrich Boell Stiftung Russia, Alla Slapovskaya, Alisa Nikulina

Soviet records from this period state that a “sanitary alienation zone” was established in the area surrounding the Mayak site. This meant that people were banned from ever living in or around the territory. But that didn’t mean that everyone was protected from the horrendous contaminates that had been unleashed.

Because there were people that still had to go to work at the Mayak nuclear facility. It’s a horrendous reality, but many of these workers were consequently exposed to the deadly radioactive materials in the area. And such contamination would have significantly raised their likelihood of developing and passing away from cancer.

Image: Alexander Blecher, blecher.info/CC BY-SA 3.0 DE

For a clearer sense of the damage brought about by the Mayak site, we can compare it against perhaps the most famous nuclear incident in history. Because the Chernobyl disaster of 1986 released huge levels of radiation into the atmosphere. Yet Lake Karachay alone was said to emit more than two times that amount.

Things were made much worse during the 1960s, when dry conditions exhausted the water levels of the lake. This ensured that contaminated dust particles were swept up from the parched basin and spread across a wider area. And a reported 500,000 people were affected by this dust, exposed to radiation levels similar to people impacted by the atomic bomb explosion at Hiroshima. Goodness me.

But efforts to deal with the incredible danger posed by the polluted site were finally made during the late 1970s. Because in 1978 slabs of concrete were placed into the lake to restrict its radioactive materials from spreading to nearby areas. By 1986 some 10,000 of these blocks had been inserted into the basin.

Yet while those slabs might help to restrict the spread of radioactivity, it doesn’t get rid of the problem. And without efforts to clean the lake, the area will remain dangerous for centuries – perhaps even millennia. Yet some experts claim that diverting the nuclear material elsewhere would actually be more dangerous than simply leaving it be.

Still, leaving the waste in Lake Karachay is itself an extremely problematic thing to do. In fact, one nuclear expert has suggested that no nation on Earth has ever had to manage a site as hazardous Karachay before. So officials will have to monitor the location very carefully for the foreseeable future.

For now, it seems that the area surrounding the Mayak facility is at least less dangerous than it was in past decades. You certainly shouldn’t drink water from Lake Karachay or the Techa River, and you can’t eat food grown around their banks. But the concrete slabs in the lake have apparently made things a little better.

Image: KIRILL KUDRYAVTSEV/AFP via Getty Images

So if you somehow managed to wander over to the edge of Lake Karachay today, would you be okay? Well, you probably wouldn’t drop dead within the hour, as you would have done in the past. But given all we know about the area, you probably shouldn’t stick around for too long.

As time goes on, soil and other materials will be dumped onto Lake Karachay. This should lead to the growth of plant life, though trees will be restricted as their roots could interfere with the concrete slabs. Basically, the situation will hopefully improve, but it’ll undoubtedly remain precarious for a long time to come.