There are plenty of old mysteries out there that we will almost assuredly never solve. It’s not that we don’t want to or anything; it’s just that in many cases, notable old mysteries and creepy, long-forgotten unexplained events simply happened too far in the past for us to investigate properly. With events decades or centuries old, we can’t interview witnesses and get to the bottom of strange happenings.
So, many of history’s mysteries are best left to wonder about and hypothesize over without truly knowing any answers. It’s a little bit fun in that way, isn’t it? Sure, we’d like to know how the past’s mysteries actually happened, but wondering about the possibilities makes for fun debates and discussions with friends.
And that’s what we are today. In this list, we’ll take a look at ten mysteries that will almost certainly never be solved. From the paranormal to the bizarre and unsettling to the just plain creepy, these mysteries have no known answer. And they probably never will! Unless you feel like jumping in after reading this list and doing a little at-home detective work for yourself, that is!
Related: Top 10 Places On Earth With Reoccurring Unsolved Mysteries
10 The Circleville Letters (1977)
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It all began in the summer of 1977 when a woman in the small town of Circleville, Ohio, received an anonymous letter in the mail. She opened it and discovered bizarre, crudely scrawled handwriting. The letter told her that some unnamed person had been observing her house and knew that she had kids.
Furthermore, the letter writer knew something no one else did: that she was having an affair with the local school superintendent. Alarmed, the woman rightly felt fear that somebody was watching her and keeping a close eye on her family. But things would only get so much worse from there.
Several weeks later, the letter writer mailed another letter to the woman’s husband. The writer informed him of the affair and encouraged the husband to kill both his wife and the school administrator with whom she was cheating. After two weeks and no action taken, the letter writer fired off yet another anonymous piece of mail to the husband, goading him to take action.
Enraged, the husband grabbed a gun and jumped into his car, telling witnesses that he was going to go kill the letter writer—implying he knew the person’s identity. But while driving in a furious rush to confront whoever was writing the letters, the man died in a terrible one-car accident.
For years after, the letters kept coming. And they didn’t just come to the woman who got the first one, either. Dozens and dozens of Circleville residents received letters for nearly the next two decades. Shockingly, the letters contained personal information about themselves, which people had no idea how this random stranger had learned.
The letters also contained wild accusations and specific violent threats, too. That got the cops involved. However, they were never able to figure out what was going on. To this day, the letter writer and their motives for turning Circleville upside down both remain a complete mystery.[1]
9 The Lead Masks Case (1966)
On August 20, 1966, a young boy flying a kite on a remote and tough-to-access hill outside Rio de Janeiro, Brazil, found the bodies of two men. He ran down the hill and reported the findings to the cops. But because of the treacherous terrain, coroners and first responders weren’t able to get up the hill to recover the bodies until the next day.
When the police and firefighters did arrive, they found a very strange scene: Two men were lying next to each other and partially covered by grass. The weird part was that each deceased man wore a formal suit, a waterproof coat, and a lead eye mask. There was no feasible reason for them to be wearing the waterproof coat or the lead eye mask up on the hill, and cops were quickly very confused.
Alongside the two corpses was an empty water bottle, and a packet with two wet towels inside. Then, most cryptically, there was a small notebook that had a set of timed instructions written inside in Portuguese. The instructions’ rough translation into English was: “16:30 be at the specified location. 18:30 ingest capsules, after the effect protect metals await signal mask.”
That creeped out investigators even further, of course. The two men were eventually identified as two Brazilian electronic technicians named Manoel Pereira da Cruz and Miguel José Viana. They had been last seen by their families three days prior to the boy finding their bodies on the hillside.
But while a coroner’s report might have actually allowed authorities to come up with some answers in the case, it never came through—at least, not in time. The coroner’s office in Rio De Janeiro was very backed up with cases and medical exams at the time. So the bodies sat for days on end, waiting to be autopsied. By the time the coroner was finally able to get around to it, their organs were too badly decomposed to figure out whether the men had ingested any notable substances prior to their deaths. Since then, the discovery has been a bizarre and persistent mystery.[2]
8 The Green Children of Woolpit (1100s)
At some long-forgotten point in the middle of the 12th century, two young children with green-tinted skin suddenly appeared out of nowhere in the tiny village of Woolpit in Suffolk, England. The duo was determined to be brother and sister based on their resemblance and ages. They spoke in a bizarre, unknown language that Woolpit residents couldn’t understand.
Most unusual, though, was that their skin was tinted green and gave off a very unsettling appearance. And they would only eat raw broad beans when prompted to take food. Even more bizarrely, they had entered the village from somewhere completely unobserved, and nobody knew from where they came or what their lives had been like before they showed up.
Over time, the villagers tried to get the pair to settle into a new life. Sadly, the boy died soon after he reached the village. He had been sickly, and he wasn’t long for this world, no matter what the villagers could offer him. The girl was eventually nursed back to full health, though, and as she got better, she even lost the green tint on her skin.
In time, she was baptized, and she even learned to speak English, too! As the legend goes, upon learning English, she reportedly told villagers that she had come from a land where the sun never shone, the earth was covered in permanent twilight, and everything there was green. According to one report from the time, she claimed the place was called Saint Martin’s Land.
Obviously, there is a lot to be skeptical about with that story. For one, it happened nearly a thousand years ago, so there’s no way we can get any more reliable information than the reports that came out from that long-ago time. Plus, historians aren’t even completely sure when it happened!
Experts know it was in the 12th century without a doubt, and they think it was during King Stephen’s reign, which lasted from 1135 to 1154, but they aren’t even 100% sure on that part. So we will pretty clearly never know the real story behind the Green Children of Woolpit. That’s a shame because it makes for an incredibly creepy tale![3]
7 The Mary Celeste (1872)
On December 4, 1872, travelers in the Atlantic Ocean just off the coast of the Azores a few hundred miles west of Portugal came across the Mary Celeste. The Mary Celeste was a Canadian-built ship that was owned and registered by an American merchant brigantine firm. It had been filled with valuable cargo and was supposed to be on its way to Europe at the time.
About a month before, on November 7, the ship had left New York City with a plan to go to Genoa, Italy. It had a full stock of alcohol that it was going to drop off in Genoa—expensive provisions that were still on the ship when the Canadian brigantine Dei Gratia found the Mary Celeste floating off the Azores.
The creepy part was that when the Dei Gratia came up to it, they found absolutely no human activity on board the Mary Celeste. The alcohol stocks were full, and the crew provisions were equally full, suggesting nobody was starving to death or anything like that.
Furthermore, all the crew’s personal belongings on the Mary Celeste were left completely undisturbed. But the crewmen who were supposed to be working the ship were nowhere to be found. Every last one of them was missing, having vanished without a trace! The ship’s log didn’t give further clues, either, with its last entry having come ten days earlier.
It was even more bizarre that the ship was still seaworthy and still floating just fine. It had been under partial sail when the Dei Gratia found it, and interestingly, its lifeboat was missing. But with nothing else gone and the ship showing no signs of having been battered about in a storm, what could have happened?
The men who had crewed up in New York to work on that fateful voyage of the Mary Celeste were never heard from again, and nobody knows what happened. Was it a mutiny? Piracy? An insurance scam by the ship’s owners seeking to salvage its goods and needing to kill the crew to make it happen? The mystery will likely live on forever.[4]
6 The Flannan Isles Lighthouse Mystery (1900)
On December 15, 1900, a steamship named Archtor, on its way from Philadelphia, Pennsylvania, to Leith, Scotland, noted that a lighthouse that was supposed to be operational on Scotland’s far-flung Flannan Isles was not in good working order during a rough storm. Three days later, when the Archtor docked in Leith, they reported the bad lighthouse situation to the Northern Lighthouse Board.
Immediately, the board sent a relief ship out to the remote Scottish isle to figure out what was going on. Due to adverse weather, though, the relief ship did not reach the lighthouse until nearly ten days later, on December 26. Once there, they expected to find three men working at the lighthouse—James Ducat, Thomas Marshall, and Donald McArthur—as they were tasked to do at the time. But when the relief ship’s men came up to the lighthouse at noon on December 26, they couldn’t find any of the three men anywhere around the island.
The mystery was unsettling from the star. For one, the lighthouse’s flagstaff had no flag. None of the lighthouse’s provision boxes were left on the landing stage to re-stock as they should have been. And the relief ship’s men could find no sign of the lighthouse’s three-person crew anywhere nearby.
When the relief men reached the compound itself, they found the entrance gate closed, the beds inside unmade, and the rest room’s clock unwound. They also found lamps that had been cleaned and refilled but sitting harmlessly inside. Wherever the lighthouse’s vanished staffers had gone, they hadn’t thought to take the lamps with them.
No sign of the three keepers was ever found beyond that discovery. And their bodies never washed on shore or were otherwise discovered, either. It’s unclear what happened to the men. To this day, despite several different theories, including opinions that they could have set out on their own to live a new life or possibly been met with some unforeseen tragedy that swept them into the ocean, their whereabouts are completely unknown.[5]
5 Patomskiy Crater (1949)
In 1949, a Russian geologist named Vadim Kolpakov discovered a massive and extremely bizarre crater located in a rural part of southeastern Siberia not far from Lake Baikal. This rock formation has come to be known as the Patomskiy Crater—and even though it’s massive and completely unique to the area, geologists and other scientists have no idea how it got there.
The crater is basically a very large mound made up of shattered limestone blocks. It sits on the slopes of Russia’s Patom Highlands within that nation’s Irkutsk reason. At its base, the crater’s diameter is about 520 feet (158.5 meters), and its off-shoots are more than 40 feet (12 meters) high. In the center of the crater is a cone with a ring-shaped crown, and the height of that smaller mound is nearly just as tall as the carter’s outside walls.
The entire thing is absolutely massive, with its inside volume estimated to be well over 8 million cubic feet (226,534 cubic meters) and its weight tabbed at approximately one million tons. Yet, despite being so big and so unbelievably out of place relative to the rest of its surroundings, nobody knows how it got there or from where it came. There are theories, of course, with the leading one being that it was a meteorite that landed on Earth in a flourish. Others claim it came about from volcanic activity, or even is caused by a deep pocket of unusual natural gas flow.
The most vocal theorists believe the Patoskiy crater is an off-shoot fragment from the same meteorite that landed in nearby Tunguska in the early 20th century. But if that were the case, the crater’s determined age wouldn’t match up—science has found it to be about 300 years old, and not roughly 40 like Tunguska at the time that Patomskiy was discovered.
Regardless, whatever event caused the Patomskiy crater is completely unknown still to this day. Scientists continue to observe it to see if they can learn more about it, but so far, no dice.[6]
4 The Disappearance of Flight 19 (1945)
On December 5, 1945, five Avenger torpedo bombers flying for the U.S. Navy as Flight 19 on a mission just off the coast of Florida completely disappeared and were never heard from again. The five bombers had been sent out on a training flight from Naval Air Station Fort Lauderdale in south Florida. At some point in the flight, though, the main navigator in the first plane became disoriented as to where the group was going, and they lost track of their direction heading back to the mainland.
Tragically, the planes were never seen again, and all 14 men who were flying as part of the crew on those five planes that day were lost forever. To make matters even worse, a Martin PBM Mariner flying boat was dispatched to go search for the men on a recovery mission—and it, too, was lost along with its 13 crew members during the search for Flight 19.
There have been many theories about what happened to Flight 19. Some say the tricky situation in the Bermuda Triangle was the thing that caused those planes to disappear. Others say they were attacked and swooped up by aliens or other even more fanciful (and frankly, ridiculous) theories.
The most common and sensible prevailing theory is that the flight leader, Lieutenant Charles C. Taylor, struggled to navigate after his compasses stopped working. Then, he mistakenly thought a series of small off-shore islands east of land was the Florida Keys to the south. So he continued heading out over the open sea and away from land. As for the PBM search aircraft, the Navy officially believes it was lost in an explosion in mid-air that occurred while it was searching.
Of course, the strange thing about all this is that no parts of the airplane wreckage or anything else were ever found. Nothing washed ashore, no wreckage or remains were ever uncovered, and nobody has any idea where or even if the planes and the men who died inside them are somewhere at the bottom of the ocean. The actual fate of the crews involved and the specific timeline of events regarding what happened that day, will likely forever remain a mystery.[7]
3 The Max Headroom Broadcast Signal Intrusion (1987)
On the night of November 22, 1987, television viewers in Chicago, Illinois, were treated to quite a spectacle. An unknown person hijacked two different broadcast signals in the major midwestern city—and their identity has never been discovered. First came the short hijacking of a major network. It was the 9:00 pm newscast hour for WGN-TV.
The station was in the middle of a sports segment when suddenly, a person wearing a Max Headroom mask and swaying erratically in front of a metal panel appeared on screen. There was a loud buzzing sound that accompanied the video hacking. The interruption lasted only 17 seconds, though, as WGN had engineers actively working that night, and those staffers were able to regain control of their channel and get the screens pointed back to their newscast.
Two hours later, the second and much larger intrusion occurred. It happened on PBS affiliate WTTW during a broadcast of a Doctor Who” episode called “Horror of Fang Rock.” PBS didn’t have any engineers on duty at the time, as they were simply running canned shows. So the signal takeover was more sustained, lasting for more than 90 seconds in total.
When the Max Headroom-masked figure appeared on screen, he made bizarre references to things like New Coke, the cartoon TV show Clutch Cargo, a local Chicago-area sportscaster, and other random topics. Then, a woman’s hand spanked the masked figure’s bare butt with a flyswatter while he yelled, “They’re coming to get me!” The hijackers then ended the pirated transmission on their own and disappeared away into the night.
Whoever was behind the Max Headroom stunt has never been found. The Federal Communications Commission looked into the stunt, but they were unable to figure out who might have done it or what their motives were.
Now, nearly 40 years on, it’s unlikely we will ever know who was behind the shocking and exceedingly random hacking. Even if it was a harmless prank, the FCC and major television networks were rightly concerned that other hackers could use mass broadcasting like that for nefarious purposes. (And then social media came around, and now, well, here we are…)[8]
2 The Lost Colony of Greenland (1400s)
The Norse settled Greenland in about the tenth century or sometime earlier. For the next five hundred-ish years, they kept an active colony on the unforgiving terrain. But then, in the very late 15th century, that colony completely disappeared.
All the people in it left and left behind a good deal of their supplies and other things as though they just vanished into thin air. Now, well over 500 years after the colony’s complete loss, historians and archaeologists are still at a standstill over why it happened and what became of the people who lived there.
There are many competing theories as to why the lost colony of Greenland became, well, lost. Some believe environmental changes made life there harder, forcing people to flee. Others think local Inuit and other indigenous populations raided the colony to such a great degree that people were murdered and taken prisoner.
Others think that a lack of support over time from European Norsemen frustrated the colonists, who then set out looking for a new life elsewhere. A late 15th-century plague that swept through Iceland and Norway is even thought to be a cause, as it left many farms and homesteads available for the taking and could have inspired colonists to return home and settle down.
The most bizarre part of the entire mystery is that people seem to have left the colony in a very orderly, measured fashion. If Inuit raids were to blame for the disappearance, the colony itself would have been left a trashed and messy disaster when Viking sailors later came upon it to discover it had been deserted. It wasn’t trashed, though, and no current-day archaeological evidence from these ancient farm sites indicates any sign of attack.
Starvation is thought to be unlikely, too. Were the colonists impoverished to the point that they simply wanted to flee for better land further south? Did they grow weary of the difficult world of living in Greenland? It’s been so many centuries now, and we will almost certainly never know the answer.[9]
1 The Dancing Plague (1518)
In July 1518, a woman named Frau Troffea reportedly began dancing uncontrollably in the city of Strasbourg, Alsace, in what is now modern-day France. She took to the streets and, for days on end, never stopped dancing. There was no apparent motive behind her dancing—at least none that people could readily figure out.
Before too long, other people started joining her in the streets doing their dances, too. In total, the dancing situation ended up turning into a very notable and very strange event of mass hysteria. Based on records documenting the situation, historians today estimate that anywhere between 50 and 400 people took part in the dancing plague. And it lasted for weeks on end!
There is obviously plenty of confusion regarding why this “plague” occurred, and why Frau Troffea ever was compelled to dance in such a way for so long. The most common theory is that it was the manifestation of some sort of stress-induced mass hysteria.
Other competing theories include things like the population suffering from ergotism caused by fungi present in the rye they farmed and used for sustenance. Some even question whether there was a religious explanation for all the dancing. In the end, some historians have even found documents claiming that dozens (or even hundreds!) of people may have died from exhaustion after weeks of endless dancing.
Whatever the case may be, the Dancing Plague of 1518 remains one of the strangest human-centered phenomena ever recorded. While it was almost certainly some form of mass hysteria or mass psychosis (and not, like, aliens forcing them to dance), the exact causes of and reasons behind this “plague” and its beginnings will likely never be known.[10]