During The Golden Age of Piracy, thousands of buccaneers terrorized the high seas and became legends. Their exploits spawned fantastic stories of larger-than-life characters, billion dollar heists and buried treasure that to this day, has never been found. Are these stories simply tall tales, or is the truth stranger than fiction?

There are islands throughout the world that despite their scenic and tranquil beauty, evoke nothing but fear and dread. These islands are riddled with dark histories, unspeakable tragedy, and the belief by locals that they are cursed. Are the misfortunes experienced by the inhabitants of these islands simply a series of tragic coincidences, or is it possible that scattered across the planet there are... Islands of the Damned?

People go missing every day, but throughout history, there have been strange and eerie disappearances that continue to capture the world's attention. Whether it's the missing case of a world famous icon, like Amelia Earhart, or even entire groups of people that seem to vanish without a trace, these mysterious disappearances have spawned countless theories, but no definitive answers.

There are stories of advanced technology, from the ancient past, that seem too impossible to be true. Some are spoken of in legends and myths, while others can be seen today with the naked eye. These technologies challenge everything we think we know about the innovation of our ancestors. Is our most cutting-edge modern technology, merely reinventions of those that existed thousands of years ago? And if it is, where did these incredible lost inventions go?

Our five senses--sight, smell, hearing, taste, and touch--construct the reality of the world around us, like a blank canvas continuously painted and repainted over every day. For each person, this portrait of reality is slightly different, but we more or less agree that the sky is blue, lemons are sour, and horns are loud. But what about when one or more of your senses is heightened, changed, or even taken away all together? Do people with these radically-altered senses show us that each of us has limitless sensory potential, waiting to be unlocked? And is it possible that we have a mysterious "6th sense," one that is currently UnXplained?

For decades, the debate has raged as to what exactly Unidentified Flying Objects--or "UFOs"--really are. Theories have been put forth that attribute them to everything from secret military aircraft to weather phenomena and more. But by far, the most controversial theory is that these objects are, in fact, spacecraft that have been piloted to Earth by extraterrestrial beings. It's a seemingly outlandish notion, but could it be true? And if so, how much does the government know about these spacecraft--and the aliens who are visiting our planet?

There are many puzzling artifacts from around the world that challenge everything known about the technological capabilities of distant ancestors; some ancient objects are so mysterious they've spawned endless debate and theories.

Scattered across the globe lie mysterious ruins that are buried in sand-swept deserts, perched atop towering mountains, and shrouded in the heart of dense jungles. These age-old structures stand as silent sentinels from the past, their true history seemingly erased by time. Can modern archaeology unravel the enigma of how-and why-these wonders were built?

There's nothing more fascinating than a code that can't be cracked. For centuries, mankind has devised ingenious ways to hide valuable information using everything from enigmatic puzzles, to complex ciphers and secret symbols. If history's unbreakable codes can be deciphered, could we unlock answers to some of the greatest mysteries of both the past and present?

Since the dawn of humanity, tales of monstrous creatures lurking in the shadows of our world have sparked both fascination and fear. Today, we often dismiss these accounts as the stuff of myth and legend, but are we overlooking a potentially terrifying reality? With scientists discovering as many as 18,000 new animal species every year, isn't it conceivable that there could be real-life, flesh and blood monsters living among us?

During the Middle Ages, the Vikings were infamous for being a bloodthirsty band of seafaring warriors; historians are learning surprising new things about this Norse society.

Abandoned cities. Ancient cultures nearly erased by time. And colossal empires that simply vanished without a trace. How does a civilization become "lost"' What could cause once-thriving groups of people to just abandon their great cities, never to return' Can modern scientific knowledge help answer the unsolved questions surrounding these lost civilizations, or is there something more mysterious at work'

Remarkable feats of engineering from our ancient past span the globe. Some are amazing in size. Others in sophistication. Some are so strange they border on inexplicable. Did the ancients have advanced scientific knowledge that has been lost to time? How--and why--did they fashion these incredible wonders?

All over the world are forbidden 'triangles'--mysterious regions where ships, planes, and people enter and then just disappear. They are found in Bermuda, Alaska, Japan and elsewhere. But why? Do these locations defy the laws of physics? Or is it possible that there are some places on Earth that we are simply not meant to go?

Throughout the world, there are ancient structures that defy explanation because even with today's technology they would be nearly impossible to duplicate. How were ancient civilizations able to build such extraordinary structures? And what purpose did they serve?

A look at whether time travel has already occurred, on purpose or by accident, and scientists who believe it is theoretically possible.

For centuries, archaeologists have tried to unravel the mysteries of how – and why – certain incredible structures like the Great Pyramid at Giza, the staircase at Loretto Chapel, and Coral Castle were built. Will we ever find the answers? Or, might these structures have been intentionally constructed to perpetually mystify us?

More than 80% of the Earth's oceans remain unexplored, and in many ways, the underwater world is the final frontier. As new technology allows us to explore oceans and deep lakes more than ever before, what will we find? Will we discover profound secrets about the oceans? Underwater ruins that were lost for thousands of years? Or perhaps something even more extraordinary?

All over the world, there are giant monoliths that our ancient ancestors carved out of solid rock. But what was the purpose of these huge stone monuments? Did they serve some kind of ritual function? Were they intended to honor the gods? Or is it possible that, as some believe, certain monoliths were actually designed to conduct energy?

During World War II, a number of persistent mysteries were born including unexplained stories about everything from lost gold, to secret societies and highly advanced technology.

Since the dawn of human history, mankind has faced the ever present threat of organisms so small, that they are invisible to the naked eye. While modern science has stopped many dangerous viruses and bacteria in their tracks, there is a growing concern, that contagious germs could be traveling through the deadly vacuum of space. Will Earth's next pandemic come from another world?

Many mysteries of planet Earth are far from understood. How was Devil’s Tower formed? Or why do some people get struck by lightning multiple times? While some may write off these as random occurrences, might they instead point to a new understanding of not only our planet’s past – but also its future?

Deadly dances. Masters of manipulation. Mass suicides. Murder. Many of the world's deadliest cults ventured down dark, dangerous rabbit-holes of twisted ideologies, persuading their members to kill--sometimes other people, sometimes themselves. Is there any sense to these sinister groups' Or will the unreckoned forces behind such Deadly Cults remain...UnXplained?

A dog that can detect cancer faster than doctors using sophisticated equipment. A horse that can read your mind. And birds that can sense disaster days before it happens. What gives animals these extraordinary powers? We like to think of ourselves as the peak of evolution--but what if we're wrong?

Ancient ruins fascinate us, and some archaeological finds are so baffling that they challenge everything we know about the past. Will we ever learn the truth about these mysterious ruins? Or will they continue to present more questions than answers?