Examining Scotland's long-standing aquatic mystery, which remains unsolved after centuries of theories, sightings and searches.

Examining the world-shaking events of November 22, 1963 in Dallas, Texas which, for many, have still not been satisfactorily explained over half a century later.

Examining the enduring mystery surrounding the group of 16th-century settlers who seemingly vanished without trace from Roanoke Island, off the coast of North Carolina.

In 1997, thousands of people across Phoenix witness a series of strange lights unlike anything they've ever seen. Could this be one of the largest-scale UFO sightings in history, or is there another explanation?

One of the holiest and most powerful biblical relics has been missing for over 2,000 years. While some believe the Ark of the Covenant was destroyed, many think not. Could new clues finally tell us what happened?

In 1930, a NY Supreme Court justice linked to Tammany Hall and FDR disappeared. The unsolved case dominated media for decades. Could a deathbed confession finally reveal what happened to Judge Joseph Crater nearly a century later?

Blackbeard is said to have stowed away a treasure worth millions of dollars. After centuries of searching, the legendary hoard remains missing. As new evidence is unearthed, the mystery endures: what became of Blackbeard's lost treasure?

An ancient mechanical device found on a 2,000-year-old shipwreck has become known as the world's first computer. The machine is far more advanced than historians thought possible, yet its origin and true purpose remain a mystery.

More than 4,000 years old, the pyramids of Egypt are among Earth's most celebrated architectural marvels. But no one fully understands how or why they were built. What is the true purpose of Egypt's astonishing pyramids?

In 1971, D.B. Cooper hijacked a plane, demanding four parachutes and $200,000 before jumping out and disappearing, making it the only unsolved air piracy case in history. Could new evidence uncover Cooper's identity?

It's one of America's most mythic UFO incidents--a 200-yard swath of debris that landed near Roswell. The deeper researchers dig, the more perplexing the story gets. It's a mystery that's endured for 80 years. So what really crashed in Roswell?

The search for the Northwest Passage leads to a historic expedition that sets sail into a labyrinth of ice and is never heard from again. That disappearance sparks a search spanning two centuries. What killed the men of the Franklin Expedition?

On February 14th, 1929, one of the most shocking murders in mob history goes down in Chicago--and becomes known as the Valentine's Day Massacre. So who carried out the Valentine's Day Massacre? And why?

Sightings of the Yeti, a creature of myth and legend, has been recorded for thousands of years throughout the Himalayas and surrounding regions. Could this creature be hiding in plain sight? And if the Yeti does exist, what is it exactly?

Amelia Earhart, the world's most famous female pilot, takes off on the final leg of a record-breaking flight. But she never arrives at her next stop. The search for this famed flier has revealed conflicting stories. What really happened to Amelia?

No ship in history has searched the extreme depths of the Bermuda Triangle - until now. The most advanced search vessel of its kind will deploy cutting-edge technology in an effort to solve the mysteries of the Bermuda Triangle.

No ship in history has searched the extreme depths of the Bermuda Triangle - until now. The most advanced search vessel of its kind will deploy cutting-edge technology in an effort to solve the mysteries of the Bermuda Triangle.

On 20 July 1973, martial arts superstar Bruce Lee died under mysterious circumstances in Hong Kong. Bruce's brother, Robert Lee, was never satisfied with the official cause of death - a fatal reaction to aspirin.

Harry Houdini left behind a diary that had been kept from the public, held under lock and key by a wealthy New York City family. Now, magician and Houdini expert Bill Kalush has finally secured access to these pages.

An investigation into the unshakable claims of Roger Miklos, one of America's most eccentric, controversial, and accomplished treasure hunters.

One of World War II's greatest unsolved mysteries: an incomparable work of art worth half a billion dollars, lost without a trace. Perhaps the single most valuable object the Nazis ever stole. Where is the famed Amber Room?

A union activist disappears from a Detroit suburb. After 45 years, it remains one of the most notorious missing person cases. Jimmy Hoffa's disappearance features more twists and turns than a Hollywood movie, but the question remains: where is he?

In 1959 nine Russian hikers died in mysterious circumstances in the northern Ural Mountains. Numerous theories have been suggested, but just what did make them flee their tent in the middle of the night in sub-zero temperatures?

As the Cold War ramps up, a well-dressed man is found dead within miles of a nuclear testing site on a tranquil Australian beach. It's a case that's obsessed an army of sleuths for over 70 years: Who is the Somerton Beach man, and how did he die?

After a series of dark and ominous events, an unassuming family home on Long Island becomes America's most notorious house. Half a century on, it's spawned a tidal wave of books, documentaries, and films; but do haunted houses really exist?

It's a treasure coveted by everyone from Roman Emperors to Adolf Hitler - a sacred object said to hold incredible powers of healing, resurrection and immortality. It may be the world's most sought-after relic, but what is the Holy Grail?

One of the most chilling aviation mysteries in modern day: a Boeing 777, carrying 239 people, vanishes over the Indian Ocean. Nearly a decade later, the whole world still wonders - what really happened to Malaysia Flight 370?

A cold case that ignites every parent's worst fears: on Christmas morning, 1945, five siblings vanish from their home in West Virginia during a raging fire. The devastated Sodder family spends the rest of their lives trying to find out what happened.

It might be the world's most mysterious book: a medieval manuscript filled with unidentifiable drawings, written in a secret language so complex that even the best codebreakers can't crack it. What is the Voynich Manuscript, and who wrote it?

A spree of gruesome murders shocks Victorian England and the world. The homicidal maniac responsible remains a mystery. Can history's most notorious serial killer ever be identified? Who is Jack the Ripper?

When the infant son of an aviation legend is snatched from his crib at home, it ignites a media firestorm. After a nationwide manhunt, the supposed culprit is brought to justice.

A series of unexplained deaths near Chicago in 1982 starts a nationwide panic. The victims are connected by one frightening detail: cyanide-tainted capsules of Extra Strength Tylenol.

Looking at how new evidence and technology may finally be able to identify the mysterious late-1960s serial killer who taunted investigators with cryptic ciphers.

More than 4,000 years old, the pyramids of Egypt are among Earth�s most celebrated architectural marvels. But no one fully understands how or why they were built. What is the true purpose of Egypt's astonishing pyramids?�

During World War Two, the Nazis stole vast amounts of art, gold, silver and currency, stashing it across Europe. While some has been recovered, much more is still missing. Where did the Nazis take their stolen loot? And can it ever be found?

It's one of the most famous stories from the Bible. Now, can scientific evidence prove if there really was a great flood? And if so, what happened to Noah's Ark?

A mysterious arrangement of stones that have adorned the English countryside for millennia. But to this day, nobody knows how the landmark was built or why. Can modern technology finally unlock its secrets? What is the true purpose of Stonehenge?

A mysterious arrangement of stones that have adorned the English countryside for millennia. But to this day, nobody knows how the landmark was built, or why. Can modern technology finally unlock its secrets? What is the true purpose of Stonehenge?

It is a legendary ancient city, said to be overflowing with gold. For centuries, explorers put their lives on the line searching for it. As the endless quest to uncover this fabled city continues, will anyone ever find it?

In 2016 a mysterious illness strikes dozens of government officials in Cuba. Over the next few years, hundreds more are afflicted. Investigations raise more questions than answers. What is the true cause of this phenomenon known as "Havana Syndrome?"

2,000-year-old geoglyphs made in the Peruvian desert span over 50 miles, drawings so massive they can only be seen from the air. Can new research finally unravel their secrets? What is the true purpose of the incredible Nazca Lines?

She was the last pharaoh of Egypt and one of the most famous queens of all time, but her death has been shrouded in mystery. Cleopatra's tomb have been lost for over 2,000 years. Can new evidence uncover Cleopatra's missing tomb?

In July 1996, one of the worst aviation disasters in American history leaves 230 people dead and countless questions unanswered. It's a tragedy that changes the aviation industry forever, but what caused the explosion of TWA Flight 800?

The history books say Adolf Hitler committed suicide in the final days of World War II. Did the Nazi leader really die in Berlin, or was he able to escape? And if the infamous dictator really did flee, where did he go?

During World War II, Japan plunders a fortune worth hundreds of billions of dollars from occupied countries, but to this day its whereabouts are unknown.

It's one of the most infamous crimes in American history: the gruesome murder of a young beauty, unsolved for decades. There's a long line of suspects, each more mysterious than the next.

In a perfectly planned robbery, thieves steal half a billion dollars in masterpieces from the Gardner Museum in Boston. It's been three-decades since the brazen heist... Who orchestrated history's biggest art heist - and why?

An Aztec king's glittering treasure vanishes into thin air, inspiring a 500-year search that spans continents. What really happened to Montezuma's lost treasure?

We look into the top theories behind the location of the Garden of Eden. Is it a physical place or a metaphor for a great migration?

The haunting image of the Shroud of Turin has captivated millions around the world. But what exactly is it that we are seeing, and how did it come to be? Is the Shroud of Turin truly an image of Jesus? Or something very different?

In 1698, Captain William Kidd raids a ship on the high seas and seizes its vast treasure... but Kidd is hanged before revealing where he stashed the loot. What happened to Captain Kidd's lost booty... and where is it now?

A perfectly masterminded plot leads to the most brazen prison break in American history. The search for the infamous Alcatraz escapees continues to this day. But is it really possible they survived--and if so, where did they go?

On February 24, 1942, military radar picks up what appears to be enemy aircraft over Los Angeles. Sirens send citizens scrambling, as troops fire artillery at the illusive targets. What exactly triggered the so-called Battle of Los Angeles?

With 500-year-old secrets, hidden in skeletons and stone, Machu Picchu is one of the most puzzling archaeological sites on earth. It's among the ancient world's most enduring riddles: Who built this astonishing complex, and why?

The death of one of history's most enigmatic rulers--Egypt's King Tutankhamun--remains shrouded in mystery 3300 years later. No one knows what ended the young pharaoh's life, but scientific advancements may be getting us closer to the answer.

Experts believed they knew what caused the Hindenburg disaster, but there may be more to this story. Whatever triggered the explosion, it didn't just spell doom for the Hindenburg but for the entire rigid airship industry.

The story of the most celebrated warrior king in history still stirs fascination more than 2,000 years after his death. But the location of his body is the subject of much debate. What happened to the mummy of Alexander the Great?

The Titanic's tragic story captures the imagination of the public and experts of all kinds, who--decades after the ship's demise--still seek answers. Can new evidence reveal more about how--and why--the Titanic sank?

The search for the most famous gold mine in the Old West has led many to perish in the pursuit of its elusive riches.

Five years after John F. Kennedy is killed by gunshot, his brother Robert meets the same fate. An assassin's bullet again changes the course of history, and the latest clues in the case are riddled with inconsistencies.

A notorious tragedy leads to one of the darkest chapters in early American history. In 1692, fear rips through the small town of Salem, Massachusetts. Accusations fly and many people are put to death. But what really sparked the Salem Witch Trials?