The Mary Celeste, 1872.

In 1872, the Mary Celeste, a Canadian ship, was found floating in the Atlantic Ocean off the coast of the Azores. The ship was carrying valuable cargo and was supposed to be on its way to Europe. However, when the Canadian Brigantine De Gratia found it, there was no human activity onboard, and the crew had vanished without a trace. The ship was still seaworthy, but the lifeboat was missing. Nobody knows what happened to the crew. The mystery remains unsolved to this day.

Potomsky Crater, 1949.

A massive and bizarre crater was discovered in southeastern Siberia, known as the Potomsky Crater, but scientists have no idea how it got there. It is a large mound of shattered limestone blocks with a diameter of 520 feet and offshoots of over 40 feet in height. Theories suggest it was a meteorite or volcanic activity, but no one knows for sure. Despite numerous observations, the cause of the crater remains unknown to this day.

The Lost Colony of Greenland, 1400s.

In the 10th century, the Norse established a colony in Greenland that lasted for 500 years before disappearing in the late 15th century. Historians and archaeologists still do not know why this happened. Some believe that environmental changes made life difficult, while others suggest that indigenous populations attacked the colony. Another theory is that the colonists left due to a lack of support from Europe or a plague that swept through Iceland and Norway. The most unusual aspect of this mystery is the orderly way in which the colony was abandoned. We may never know the true reason behind this disappearance.

The Dancing Plague, 1518.

In July 1518, a woman named Frau Trofier began dancing uncontrollably in Strasbourg, France. Soon, others joined her in the streets, and the Dancing Plague became a strange event of mass hysteria. Records indicate that anywhere between fifty and four hundred people took part in the dancing, which lasted for weeks. The exact cause of the Dancing Plague is still unknown, but historians believe it was caused by some form of stress-induced mass hysteria, or ergotism caused by fungi present in the rye. Nonetheless, the Dancing Plague of 1518 remains one of the strangest human phenomena ever recorded.

The Disappearance of Flight 19, 1945.

On December 5, 1945, Flight 19, comprising five Us Navy Avenger torpedoes, vanished while on a training flight off the coast of Florida. The planes lost their bearings, and the fourteen crew members on board were lost forever. A search and recovery mission also disappeared. The prevailing theory is that the flight leader, Lieutenant Charles C. Taylor, lost his bearings after his compasses failed. As a result, he headed out to sea, away from land. The fate of the Flight 19 crew and the specific events that occurred on that fateful day remain a mystery forever.

The Flannan Isles Lighthouse Mystery, 1900.

In 1900, during a rough storm, a steamship named Archer noted that a lighthouse on Flannan Isles was not working properly. Three missing men were supposed to be manning the lighthouse, but no one was found. Their whereabouts remain unknown to this day, and various theories exist as to what could have happened to them.

The Lead Masks Case, 1996.

A small child playing with a kite on a far off, difficult to reach hill close to Rio de Janeiro, Brazil, discovered the remains of two men on August 20, 1966. He promptly alerted the authorities to his finding, but because of the challenging terrain, first responders and coroners were unable to access the hill and recover the victims until the next day. What they saw was confusing, two guys, partially covered by grass, lying next to one other. They were both wearing lead eye masks, waterproof jackets, and formal clothes. The detectives were immediately perplexed by the strange outfit. A bundle with two damped owls, an empty water bottle, and a little notepad with timed instructions written in Portuguese were found next to the bodies. A mysterious note from 1966 said, 1630, please arrive at the designated spot. Manol Pereira da Cruz and Miguel José Viana, two deceased Brazilian electrical workers who had gone missing for three days.