Season 5

An Aztec king's glittering treasure vanishes into thin air, inspiring a 500-year search that spans continents; one of the greatest warriors of all-time amassed a vast horde believed to be worth more than $3 billion today.

Most people know it as the biblical birthplace of man -- the Garden of Eden; investigating if the Garden of Eden was just a story to explain human creation or if it was a real place.

A look at what happened to the secret hoard of the Knights Templar, a treasure of gold, silver, gems and religious relics protected by a medieval religious order.

The haunting image of the Shroud of Turin has captivated millions around the world; scientists and theologians are trying to figure out if the Shroud of Turin truly is an image of Jesus or something very different.

It's a mystery from the golden age of piracy. 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 one of the most brazen prison breaks in American history. With only a handful of clues left behind, 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, less than three months after the Japanese bombed Pearl Harbor, military radar picks up what appears to be enemy aircraft over Los Angeles. Air raid sirens send citizens scrambling, as troops fire more than 1400 rounds of anti-aircraft artillery at the illusive targets. When the smoke clears, the incident is veiled in secrecy and lies. What exactly triggered the

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 for sure what ended the young pharaoh's life, but scientific advancements may be getting us closer to the answer. Who, or what, killed King Tut?

For decades, experts believed they knew what caused the Hindenburg disaster that leaking hydrogen and ignited, causing the airship to burst into flames. 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. What caused the Hindenburg Disaster?

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. When his remains suddenly disappear without a trace, a search across the ancient world ensues. 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. Legend suggests the gold, and the land it's hidden on, are somehow cursed--yet treasure hunters still come to the Superstition Mountains looking for the hidden hoard. But where exactly is the Lost Dutchman's mine?

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. Who is really behind the killing of Robert Kennedy, and why?

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?