The Most Dangerous Caves Only Professionals Should Be Exploring

On every continent around the globe, people can visit wondrous caverns carved into existence by the long-term power of moving water, the shifting of the Earth's crust, or the melting of massive glaciers. These caves are almost alien to humans since most of us aren't accustomed to squeezing into tight corridors underground or underwater, surrounded by jagged rocks and spiky mineral deposits, in the damp darkness of the world's most forgotten pockets. For good reason, too, since exploring these caves can come with serious risks.

These natural tunnels, often tight and difficult to navigate, are prone to collapse since Mother Nature cares very little for the structural safety of such places. Feet of rock, ice, water, or dirt can insulate these areas from cell phone signals and other electromagnetic frequencies. Calling for help or pinpointing the position of trapped explorers can be nearly impossible. Some of these caves are filled with environmental dangers so powerful that unprepared humans could lose their lives in a matter of minutes without the most astute preparations. Sure, there are caves marketed as tourist attractions, but others are only fit to be explored by properly trained professionals. Here's the list of the most dangerous caves in the world that only those professionals should be exploring.

Plura Cave is under a small lake in the Plurdalen Valley. The primary way to access this cave system (and the only way to swim through the underwater sump) is by diving a half kilometer below the often-icy water's surface. As you might rightly assume, this makes the cave system extremely dangerous. Being a trained diver is necessary, but it only mitigates part of the risks involved with this exploration, as was highlighted in 2014 when two divers lost their lives in Plura Cave after one got stuck in a narrow section of tunnel. The second diver likely panicked at the sight of his colleague, which could've led to carbon dioxide poisoning due to rapid breathing. Three other divers were treated for decompression sickness.

Two deaths might not seem like a lot for one of the most dangerous caves, but in this case, it wasn't only the deaths that alluded to the hazardous nature of these underwater tunnels. The authorities, whose responsibility it was to retrieve the remains of the deceased divers, deemed the caves too dangerous for them – these trained professionals — to undergo the retrieval. Instead, friends of the unfortunate divers took the task upon themselves — refusing to leave their compatriots at the bottom of the lake — and rescued their remains so they could have a proper send-off with their loved ones.

The title for the deepest known cave in the world goes to Veryovkina in Abkhazia, Georgia, and this depth is part of what makes the cave so dangerous. Hazards such as falls, low temperatures, and flooding make Veryovkina a true contender on this list.

The cave is also prone to deadly floods. Even a little rain dripping through the numerous tunnels can quickly add up in the lower depths of the cave system, but the real danger is in the collection of these waters in underground water sources known to blast upward into the cave on short notice. If we blend that with the ease at which explorers can lose their way, the limited contact capabilities from within the cave, and the difficulties in exiting what is a four descent to the depths, a downpour can turn deadly in an instant. This has happened before. In 2018, a group of cavers working on a photography project of Veryovkina were met with torrential waters blasting through the cave tunnels, shaking the walls so heavily it must've felt like an impending collapse. Luckily, the explorers made it out in cliche fashion – that is, just at the nick of time.

A Russian caver who broke safety rules by exploring the Veryovkina alone in 2020 wasn't as lucky as the previous group. He died from a combination of a serious fall and hypothermia, and due to the sheer size of the cave system, his body wasn't discovered for nine months.

The caves in Gorner Glacier, one of the largest glaciers in the Swiss Alps, are large cavernous tunnels bored through millennia of ice melt. They're quite pretty, as most of the dangerous places on this list are, with walls of blue-white ice that look like something out of an icy winter film or horror movie, depending on how you look at it. With the potential for rock and ice falls, collapse, and rapid melting, it just might be the latter.

There's a common theme with glacier caves: They were once much safer to visit. Unfortunately, human-driven climate change has messed that up for everyone. Glacial caves, and glaciers in general, become more unstable as global average temperatures rise. In the case of Gorner Glacier in Valais, Switzerland, which has receded around half a mile in the past 50 years, it's been hit pretty hard, and it's expected to be almost entirely gone by the end of this century. That doesn't look particularly good for the caves in the glacier since rapidly melting ice isn't exactly the most structurally sound substance out there. In fact, you should probably think twice before entering the Gorner Glacier caves at all since, even if you might not experience a cave-in or dangerous falling ice and rock, you very well might be exploring on a natural slip-and-slide.

Known as the "Everest of Caves," Dark Star Cave in Boysuntov Range, Uzbekistan, is one of the most massive cave systems in the world, reaching around 3,000 feet below the ground and giving Veryovkina a run for its money.

As you might expect from a cave system so big, it's dark. Really dark. The light from the surface is mostly absorbed and diffused by the time you get into the lower cave, leaving you in total darkness. And though the caves have been fully mapped, unless you're a professional with deep knowledge of Dark Star, there's a good chance of getting lost in the twisting labyrinth. Your usual navigation devices won't work with that much natural insulation between you and the cell towers and satellites that provide your position data, and if you run out of battery power for your flashlight, you'll be left entirely blind. Something about starving inside a miles-long stone coffin doesn't sound very pleasant, so it's best to leave the Dark Star Cave excursions to the professionals.

Bufadero Cave in the Canary Islands is a picturesque cavern, a little getaway from the summer sun, or, at least, that's how it appears when the waters are calm. The cave is actually off-limits to the general public and has been listed as permanently closed. But being listed as closed doesn't keep daredevils from trespassing and putting themselves in mortal danger.

Bufadero Cave isn't dangerous at all times of the day. Instead, the danger is a lurking one, waiting for victims who are uninformed and unsuspecting. Bufadero becomes deadly when victims don't understand how the tides behave inside the cave and at what times the tides fluctuate. When the cave is at low tide, it's a beautiful cavern filled with jagged rocks that turn deadly when the tide washes in with a vengeance. "Vengeance" is an excellent word to describe it. Tidal changes inside the cave have cost the lives of several people over the years as they blast the cave with powerful waves capable of knocking victims into the rocks, turning a chill hangout into a truly deadly locale.

Krubera Cave is known as the second deepest cave in the world, having held the title before the mapping of its nearby cousin Veryovkina, and contains many of the same dangers as the number one. The cave dives over a mile down, and the passages span over 8 miles in total length. The entire cave system is a variable maze designed by Mother Nature to swallow up those who get in over their heads.

The possibility of ill-prepared cavers getting lost in this cave system is as immense as the cave system itself. Like many deep caves, the air isn't particularly warm and dry, which can cause issues on its own. Sumps in the cave are filled with frigid water, which could easily cause hypothermia with even the smallest hole in your drysuit. There are narrow passageways, some in dry tunnels and others completely submerged in water, begging for divers to get stuck, and deep caverns that require talent in repelling that likely isn't part of a beginner's repertoire. And just like Veryovkina, Krubera is prone to floods from the water tables beneath. In other words, this cave is best left to the professionals.