Here are 21 of the most mysterious facts in the world:
The Bermuda Triangle is a region in the western part of the North Atlantic Ocean where ships and airplanes have disappeared without explanation.
The Voynich Manuscript is a medieval text that has never been deciphered, and its purpose and content remain a mystery.
The Nazca Lines are a series of giant geoglyphs in the Nazca Desert of Peru that were created by an ancient civilization, but their purpose is unknown.
The Stonehenge in England is a prehistoric monument consisting of large stone circles, and its purpose is still a subject of debate.
The identity of the Zodiac Killer, a serial killer who operated in Northern California in the late 1960s and early 1970s, remains a mystery.
The Tunguska Event was a massive explosion that occurred in the Siberian wilderness in 1908, and its cause remains unexplained.
The Antikythera Mechanism is an ancient Greek device that was used to predict astronomical positions and eclipses, and its construction remains a mystery.
The disappearance of Amelia Earhart, a pioneer aviator, in 1937 remains a mystery to this day.
The Wow! Signal is a radio signal detected in 1977 that has never been explained, and it is considered one of the best pieces of evidence for extraterrestrial life.
The origins of the Easter Island statues, massive stone sculptures that dot the island, are still shrouded in mystery.
The identity of Jack the Ripper, a notorious serial killer who terrorized London in the late 1800s, has never been definitively established.
The Shroud of Turin is a cloth that is believed by some to be the burial shroud of Jesus Christ, but its authenticity remains a matter of debate.
The Black Dahlia murder, a gruesome killing that took place in Los Angeles in 1947, remains unsolved.
The Mothman, a humanoid creature with wings, was reportedly sighted in the vicinity of Point Pleasant, West Virginia, in the late 1960s, but its existence is still debated.
The Taman Shud case is an unsolved mystery involving an unidentified man found dead on a beach in Adelaide, Australia, in 1948.
The Dyatlov Pass Incident is a mysterious event in which a group of hikers in Russia died under mysterious circumstances in 1959.
The Taos Hum is a low-frequency noise that can be heard in the vicinity of Taos, New Mexico, but its source remains unknown.
The Oak Island Money Pit is a mysterious site on Oak Island in Nova Scotia, Canada, where treasure hunters have been searching for centuries.
The Georgia Guidestones are a set of granite slabs in Georgia that contain ten "guidelines" for rebuilding society after a catastrophic event, but their origins and purpose remain a mystery.
The Marfa Lights are a series of unexplained lights that appear in the sky near Marfa, Texas.
The Roswell Incident was a reported crash of an unidentified flying object in Ros