From the 17th to the early 20th century, America saw an unprecedented era of rapid western expansion. Millions moved west to lay claim to find their fortunes in gold and land for the taking in search of the American Dream.

For thousands of years, mankind has been fascinated by the idea of creating mechanical servants to make our lives easier. Today, those dreams of the past are increasingly becoming our reality.

From 1861-1865, the United States of America found itself in a bloody four-year struggle known as the Civil War. While history often focuses on the politics and battles of this bloody discord, there are fascinating stories of the people and places that played a role in the "War Between the States".

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?

Isolated along the southernmost part of the planet, Antarctica is best known as the frozen continent. Yet, this untouched land has captivated brave explorers for centuries.

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 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.

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?

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.

The idea that a handful of shadowy organizations control world events has been around for centuries. Today, the Mafia, Skull & Bones, and the Freemasons are just a few of the mysterious groups said to meet behind closed doors, keeping dangerous secrets. What are the codes and rituals that define their beliefs? And is it possible that secret societies not only shaped the events that defined the 20 th century, but will continue to shape the future?

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?

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

Urban legends are modern folklore rooted in mystery where chilling tales merge fact and fiction and blur the line between myth and reality. From the eerie reports of spontaneous human combustion and the hunt for the Highgate Vampire, to the unsettling boogeymen known as the Men in Black appearing after UFO sightings, could these thrilling legends, echoed over generations and believed by many, be more than just stories?

Throughout history, there have been men of science who pushed the boundaries of experimentation to the edge of madness. They were renegades known for bizarre and often unethical experiments involving human-animal hybrids, mind control devices, and even unimaginable torture.

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.

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?

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'

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?

For centuries, humanity has looked up at the Moon with a sense of wonder. But is the Moon just a rock floating in space? Or could it hold profound secrets—and perhaps even possess incredible powers? That is what we will try and find out.

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 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?

There are many bizarre tales involving U.S. presidents that defy explanation and are still shrouded in mystery.

Throughout history, powerful nations around the world have enlisted spies to serve as unique tools of warfare. These secret agents are often tasked with infiltrating organizations and even performing the act of assassination.