Featuring first-person accounts by military eyewitnesses, government insiders and UFO experts, this special traces what a government investigation into 144 recent sightings can tell us about what these mysterious objects are and where they come from.

The Hawaiian Islands are a study in contradictions. The fastest growing islands on earth are also the fastest disappearing. Made of one of the hardest minerals. The world's most active volcano is nowhere near the typical volcanic regions.

From Mexico's mystifying Zone of Silence to Markawasi Plateau in Peru, known for its frequent UFO sightings, were these the homes of ancient extraterrestrials?

Cities Of The Underworld

We go beneath the streets of Japan to see the latest technology that saves the city from the many natural disasters ready to strike. Head back in time to World War II to see how Hiroshima's underground offered protection from the most powerful bombs.

The discovery of the Marianas trench was one of the first puzzle pieces that lead to the understanding of the most massive process that shapes the geology of the Earth.

In 1939, a group of scientists warned FDR that Germany might be developing an atomic bomb. Roosevelt issued an order: America had to make the first weapon. We recreate the world of classified nuclear facilities.

Featuring first-person accounts by military eyewitnesses, government insiders and UFO experts, this special traces what a government investigation into 144 recent sightings can tell us about what these mysterious objects are and where they come from.

The Hawaiian Islands are a study in contradictions. The fastest growing islands on earth are also the fastest disappearing. Made of one of the hardest minerals. The world's most active volcano is nowhere near the typical volcanic regions.

From Mexico's mystifying Zone of Silence to Markawasi Plateau in Peru, known for its frequent UFO sightings, were these the homes of ancient extraterrestrials?

Cities Of The Underworld

We go beneath the streets of Japan to see the latest technology that saves the city from the many natural disasters ready to strike. Head back in time to World War II to see how Hiroshima's underground offered protection from the most powerful bombs.

A team of Americans attempts to solve one of the great mysteries of World War II. With the help of an eyewitness, they explore a mountain in the Philippines where Japanese general Yamashita is believed to have buried a vast treasure during the war.

The discovery of the Marianas trench was one of the first puzzle pieces that lead to the understanding of the most massive process that shapes the geology of the Earth.

In 1939, a group of scientists warned FDR that Germany might be developing an atomic bomb. Roosevelt issued an order: America had to make the first weapon. We recreate the world of classified nuclear facilities.

Featuring first-person accounts by military eyewitnesses, government insiders and UFO experts, this special traces what a government investigation into 144 recent sightings can tell us about what these mysterious objects are and where they come from.

The Hawaiian Islands are a study in contradictions. The fastest growing islands on earth are also the fastest disappearing. Made of one of the hardest minerals. The world's most active volcano is nowhere near the typical volcanic regions.

From Mexico's mystifying Zone of Silence to Markawasi Plateau in Peru, known for its frequent UFO sightings, were these the homes of ancient extraterrestrials?

Cities Of The Underworld

We go beneath the streets of Japan to see the latest technology that saves the city from the many natural disasters ready to strike. Head back in time to World War II to see how Hiroshima's underground offered protection from the most powerful bombs.

A team of Americans attempts to solve one of the great mysteries of World War II. With the help of an eyewitness, they explore a mountain in the Philippines where Japanese general Yamashita is believed to have buried a vast treasure during the war.

The discovery of the Marianas trench was one of the first puzzle pieces that lead to the understanding of the most massive process that shapes the geology of the Earth.

James Nesbitt's Countdown To Disaster

In 1970, British Petroleum struck oil beneath the North Sea. On the back of industrial unrest, the promise of lucrative work was too good to be true, but by 1988, with poor management within the company, a gas leak saw the untimely death of 167 men.

Engineering an Empire

They ruled over much of Europe and Asia during the Dark Ages, building stadiums, aqueducts and cathedrals. But the Byzantines' success became their downfall.

Search for the Lost Giants

The Vieira brothers travel to the Ozarks and make two possibly game-changing discoveries.

Battles BC

Discover how, after years of rivalry, a small Greek army defeated the Persians through sheer mettle and a brilliant defensive strategy.

Along with a team of archaeologists, the Vieira brothers discover new evidence about the Goshen Mystery Tunnel, while Jim investigates a giant account unlike anything he has seen before.

When Trajan was proclaimed emperor, he set out to rebuild the troubled empire and would see it reach its maximum extent of power.

The most shocking missing item of all: the iconic Ground Zero Flag, raised by firefighters on 9/11. A few hours after it was raised, this sacred relic simply disappeared.