Everybody loves a mystery, especially one that has never been solved. In today’s world, where science can provide answers to most questions, the unsolved mysteries of the world are even more fascinating to us.

It can be hard to believe, but there are still many world mysteries for which there are no obvious or easy answers. These riddles stir our imagination because they conjure up images of the supernatural and remind us of the limits of our abilities and intelligence. The greatest mysteries of the world show us that there is still much for humanity to learn and discover about our universe and ourselves.

Eight Unexplained Mysteries of the World

Cicada 3301

Since January 5, 2012, a mysterious organization that uses a picture of a cicada, or moth, has been using complex puzzles to recruit highly intelligent people. Cicada 3301 has placed clues all over the world in books, Linux CDs, the Internet, music, and even signs placed in public places.

Nobody has taken responsibility for the puzzles, but one popular theory is that an intelligence organization such as the National Security Agency, the CIA, or the British MI-6 is using the puzzles as a recruitment tool. Other popular theories are that an organization of hackers or cyber mercenaries uses the clues to recruit new members. Another theory is that the organization responsible for the mysterious cryptocurrency Bitcoin is behind Cicada 3301. What’s truly mysterious is that Cicada 3301 has never contacted any of the people who have claimed to solve its puzzles.

The Crop Circles

Starting in the 1960s the people of England were baffled when strange patterns began appearing in farmers’ fields. Some of the circles were crude, and some were complex, a few even looked like the DNA double helix. The strangest part of the circles was that nobody knew who or what was making them.

The most popular explanation was that UFOs were making the circles. The mystery has deepened because at least some of the circles have been exposed as hoaxes. Other explanations included the weather, magic, and fractals phenomena that defy the laws of physics. Crop circles have now been seen all over the world, including the United States, Australia, and much of Europe.

The Georgia Guidestones

In 1979 a mysterious individual who used the alias R.C. Christian hired the Elberton Granite Finishing Company to build a bizarre monument in Elbert County, Georgia. The monument consists of six granite slabs similar to those at Stonehenge and a stone tablet. The Guidestones contain messages in eight modern languages: English, Russian, Spanish, Swahili, Hindi, Hebrew, Arabic, and Mandarin. There are also messages in Ancient Greek, Babylonian, Sanskrit, and Ancient Egyptian hieroglyphics. The messages include mysterious advice, such as to keep humanity’s population below 500 million.

Nobody knows who paid for the monument’s construction or why, but some Christians have denounced it as Satanic and possibly related to devil worship or the New World Order.

The Green Children

During the 12th Century two mysterious children, a boy and a girl appeared in the English village of Woolpit. The children had green skin and spoke a language that nobody recognized. They added to the mystery by refusing to eat anything but bean pods. When she learned to speak English, the girl claimed she and her brother were from the land of St. Martin, where the sun never rose above the horizon. The children eventually settled in Woolpit and lived fairly normal lives, the girl even married. Their skin eventually turned a normal color.

Explanations for the green children include theories that they were space aliens or visitors from another dimension. English folklore holds that there are still descendants of the Green Children living in Suffolk, England, but they have never been identified.

The Hessdalen Light

Ever since the 1940s mysterious balls of light have been observed floating in the area near the village of Hessdalen, Norway. The lights, which are described as bright white and yellow, float above ground level and have no visible source. Thousands of people have observed the lights, which were extremely active during the 1980s.

There is no scientific explanation for the lights, which have even been videotaped and posted on YouTube. Popular theories include a mirage, grains of crystal, ionized gas in the air, plasma in the dust, and UFOs.

Stonehenge

The mysterious ring of stone structures on England’s Salisbury Plain has stirred the imagination for centuries. Nobody knows who built Stonehenge or why. Over the centuries, Druids, Atlantis, the devil, Merlin and King Arthur, and even space aliens have been credited with building Stonehenge.

Nobody knows for sure because the culture that built Stonehenge left no written records. The modern belief is that the stones formed the center of a vast center of worship. Today, Stonehenge is the center of worship for a number of modern religious movements, including pagans and Druids. Some practitioners of magic believe it to be the center of magic powers called Ley Lines.

The Voynich Manuscript

In 1912 a Polish book dealer named Wilfrid Voynich purchased a mysterious medieval book that was written in a completely unknown language and alphabet. Since then nobody—not even top British and American codebreakers from World War II—has been able to decipher the book. To add to the mystery, the Voynich Manuscript contains pictures of plants that modern botanists cannot identify.

Nobody knows who wrote the manuscript or where it comes from. It has been dated to the 14th Century and attributed to medieval writer Roger Bacon. Today a digitized copy of the work has been placed online in hopes that somebody can solve this mystery.

The Wow! Signal

Aliens may have sent a radio signal to earth in 1977, and only one man may have noticed. On August 18, 1977, Jerry R. Ehman, a professor from Ohio State University, was examining radio data from space collected by the Big Ear radio telescope in Delaware, Ohio, when he noticed something incredible: an intense radio signal that contained the alphanumeric code 6EQUJ5. The signal was detected on August 15, 1977, for just 72 seconds by the Search for Extraterrestrial Life Project (SETI). Ehman wrote "Wow!" next to the recording. Nobody knows where the signal came from, but it may have originated in the constellation Sagittarius.

Since the signal has never been repeated, many people, including Ehman, doubt it was of alien origin. In 2012 the Acreibo Observatory beamed humanity’s response to the signal back on its 35th anniversary.