Secrets are woven into the fabric of civilizations around the world. The creepy is spoken in subdued tones. The funny ones are laughed at at the dining table. Long articles are written about them and there are fierce discussions. And perhaps the best of all mysteries are the historical ones that remain unsolved. Those who used built-in cameras in smartphones and social media instant messages were still years, if not decades, in the making …
SEE ALSO: 10 puzzles solved by incredible surprise strikes.
8 The Gargoyle of Houston
In 1986, NASA employee Frank Shaw left his office one night and walked briskly to his car. He had worked a long shift and was desperate to go home. But all thoughts of a home went through his mind as he looked up at the NASA buildings and squatted a black figure in one of its corners. After that, Shaw remembered the figure resembling a humanoid creature with a cloak over his shoulders. In his shocked state, Shaw thought it might have been a gargoyle. He also claimed to have seen two massive wings protruding from his sides. 
When Shaw finally came home, he told his family what he had seen and that the "Gargoyle" had stared straight at him. When the winged creature had fled, Shaw had run to his vehicle and driven away in horror.
Of course, most of Shaw's story was skeptical, but his family rallied behind him. However, they warned him to keep his eyes a secret from his superiors so as not to be considered "crazy." Over time, Shaw kept thinking about what he had seen, and finally mustered enough courage to tell his boss despite the advice of his family. To Shaw's surprise, his supervisor told him that other employees had experienced similar sightings. A file about the creature had also been opened after the bodies of two NASA resident German Shepherds had been found maimed in the same spot where the "gargoyle" had been discovered.
Over the years, no new sightings of the creature have made the headlines. What exactly did Frank Shaw and his ancestors see in NASA buildings? That remains a mystery.
7 The Kaimanawa Wall
The Kaimanawa State Forest is a mysterious structure known simply as the Kaimanawa Wall. Alternative historian Barry Brailsford rioted in 1996, claiming that the Wall dates to the Maori settlement around 1200 years ago. He also claimed that the wall was man-made, as it is made of ignimbrite and the shaped surfaces seem to have been shaped by human hands. If these allegations were accepted as true, there would be grave financial and political consequences for Maori tribes in New Zealand. 
If the wall is actually as old as 2000 years, an old Waitaha claim would turn out to be true. The Waitaha have long claimed that their people settled in New Zealand before the Maori arrived there. This theory directly contradicts the long-standing belief that archaeological evidence shows that the first Maori arrived between 1250 and 1300, followed by others. Local tribes in the Kaimanawa region believe that the wall is just a natural formation that has been cleared away by the weather for many years.
Another theory about the wall states that the wall is probably not even a hundred years old and the last one is a reminder of what used to be a sawmill. The geologist, dr. Peter Wood noted that, in his view, the wall was created by a cooling process of ignimbrite plates and that the stones are more than 300,000 years old. The government imposed a ban on the site following these findings, effectively prohibiting further appraisal. While theories persist, any conclusive evidence of the age and origin of the wall remains elusive.
6 Valuables of Swissair Flight 111
On September 2, 1998, Swissair Flight 111 crashed into the Atlantic Ocean about 8 kilometers off Peggy's Cove in Nova Scotia. The accident killed all 229 passengers and crew aboard the McDonnell Douglas MD-11. It took four years for the search and rescue, salvage and investigation to be completed, ultimately leading to the conclusion that flammable material in the aircraft structure made it possible to spread a fire on board out of control. 
At some point after the crash, it turned out that the plane bore a Picasso painting, nearly 50 kg in cash and 5 kg of jewels, including a diamond from the American Museum of Natural History in New York. None of it was ever salvaged. For 1 year after the accident, a restricted zone with an extension of 2 kilometers was set up around the crash site. When this zone was locked, people were "free to search the environment" to search for lost valuables. While it is possible that none of the valuable objects survived the plane crash, their ultimate goal and whether anyone has already found them remains a mystery.
5 Russian Airplane in Nairobi
On December 17, 2018, a private jet landed at Wilson Airport in Nairobi, Kenya, just half an hour before closing for the day. On board the twin-engine jet were five people with foreign registration. Three days later, at half past five in the afternoon, the plane flew to Jomo Kenyatta International Airport. Just over an hour later, on the same day, the plane flew again to a new destination, Chad, this time with seven people on board. 
Well, that's not a puzzle in itself. However, it was found that the aircraft is owned by Yevgeny Prigoshin, a Kremlin insider with links to Vladimir Putin. Prigozhin was named one of 13 people interested in investigating the 2016 US election. The immigration office also refused to divulge the identity of the other passengers on the plane.
This caused a stir in Kenya, because although the aircraft was expected, but was not known by the local security authorities, whether Prigozhin was actually on board the plane. There was a rumor that Prigozhin, a Wagner group company, was seeking to secure security agreements in Kenya, exchanging training, weapons, and electoral services for mining rights. The Wagner group was associated in July 2018 with the murder of three journalists of Russian descent.
One month before the aircraft landed in Nairobi, it was reported that Kenya and Russia were cooperating in the development of nuclear technology. Whether this was the reason the mission was kept secret or something shady was planned, we will probably never know.
4 Phantom Kangaroos
At the beginning of 2019, a photo of kangaroos leaping into the snow in Australia made the rounds in social media. However, that was not nearly as strange as the phantom kangaroo sightings in the US, of all places. 
The very first sighting was reported in 1899 in Wisconsin. Then Reverend W.J. Hancock in January 1934, after several years of not seeing along with several other witnesses, a phantom kangaroo in Tennessee. This particular kangaroo was accused of killing a dog, chickens and sheep. According to several people claiming to have seen phantom kangaroos, the creatures are up to 5.5 feet tall and have glowing eyes.
A few years later, between 1957 and 1967, many reported seeing these kangaroos in Minnesota, and in 1974, hundreds experienced a kangaroo in Chicago. There were even reports of a kangaroo that struck Golden Gate Park in San Francisco in 1980. During the sightings, local zoos were contacted, but no missing kangaroos were reported. It is believed that one of the kangaroos was hit and killed by a car in 1981, but the driver and creature disappeared before investigations could begin.
3 Mzora Stone Circle
11 kilometers from Asilah in Morocco. A megalithic stone circle called Mzora watches over the hills. The existence of the circle was first realized in 1830 AD. Starting from 175 stones, the circle now consists of 168 stones, the highest being more than 5 meters high. In the middle of the circle is a wheelbarrow with a diameter of more than 55 meters. 
In the 1st century AD, the Roman general Quintus Sertorius believed that Mzora was the tomb of Antaeus, a giant who was killed by Hercules as one of his works. He noticed that the remains of an 85-foot man were found inside the circle and they were immediately covered up again. An excavation of the area in the 30s revealed neither remains nor further investigations in the 70s.
Research has shown that Mzora was built by the same culture that was responsible for the megaliths in Europe. The circle contains a Pythagorean right triangle, as it is used in similar megalithic structures in the UK.
As with other megalithic circles, it was assumed that the stones were used as calendars and to monitor the coming seasons. Others believe that Druids worshiped on the stones or that they were runways for alien craftsmen. But the true purpose of Mzora remains unknown.
2 The Missing Volcano
In 1469 a mini-ice age struck Europe. Flora did not bloom at all and there were reports that fish were frozen as they swam around in ponds. Four years ago, the crowds attending the wedding of King Alfonso II of Naples reverently looked up to heaven as the sun went down. After this day, the weather in Europe became bleak. In Germany, flooding broke out as coffins were unearthed in cemeteries, entire villages were swept away and the citizens of Poland drove by ship when the rain rained incessantly. What no one noticed was that a huge volcano erupted thousands of miles away, causing an ash cloud that was so large that it covered the earth. This led to the coolest decade in many centuries. 
In 2009, scientists on expeditions in Antarctica and Greenland discovered a sulfur-containing layer in the snow strata of 1809 and 1810. The findings revealed that a volcanic eruption had occurred, the debris nearly 50 kilometers in had shot the air. They had found the consequences of the volcano that had erupted thousands of years ago. The only problem was that they could not find the volcano itself.
Further research in 2012 showed that the climate catastrophe of the 15th century was caused not only by a volcanic eruption, but by two outbreaks. The volcano, however, remains missing. Some have suggested that the eruptions were so violent that the volcano might have been torn apart. But until evidence is found, that remains just a theory.
1 The Hunt for the Golden Owl
In the early 90s, the author Max Valentin hid a bronze sculpture of an owl in flight on the French mainland. Valentin was the only person who knew the location of the owl. He then published a book entitled The Hunt for the Golden Owl, in which he conducted a treasure hunt with no time limit. The book contained puzzles that had to be solved to find the little owl. The prize was not just the bronze sculpture, but a statuette of the original owl in gold and silver worth a million francs.
The book also contained several rules, including the prohibition that the winner of the treasure hunt speaks to the public or the media about the place of the owl or the solutions to the puzzles in the book.
Max Valentin has since died and his publishing house has ceased his business, but the situation of the small bronze owl remains a mystery. The creator of the silver and gold owl, Michel Becker, retrieved the property in 2009 by court order, but tried to auction it in 2014. Fortunately, the owl's status was protected and had to be removed from the auction. Becker is still in the possession of the owl today. 
Before his death, Max Valentin is said to have written a solution book to the riddles in his original book, in which his son records this document; in honor of the father that the bronze owl is found by someone who can solve the puzzles.