Season 4

500 years before the Inca, a band of warriors called the Chachapoya built the greatest stone monument in the Americas. It's three times the size of Egypt's largest pyramid, yet they disappeared without a trace.

The Confederate Army, in an attempt to turn the tide of the Civil War, launched a new and daring weapon--a forty-foot submarine. The H.L. Hunley, armed with a primitive torpedo, destroyed a mighty Union warship, yet its crew never made it home.

The giant stone heads of the Olmec have amazed and mystified archaeologists for more than 150 years.

In a new expedition, Kara Cooney and Charles Ingram look for evidence of the Barbary Pirates at the bottom of the Mediterranean Sea.

Join the search for golden artifacts from Jerusalem's Temple, stolen by the Romans 2,000 years ago.

The search for the treasure of the Temple continues.

For centuries, Europeans heard legends of a mythical city in the heart of the Sahara, the source of endless caravans of gold, but it took 500 years to find.

Travel deep into the heart of the Cambodian jungle to discover a magnificent stone temple that was built on a scale unparalleled in human history.