Archaeology

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

Neither Spanish settlers nor anyone since has been able to tell who built these strange California rock walls.

This famous archeological mystery may be an ancient example of movable type.

A fantastic castle rumored to be the birthplace of King Arthur.

This shallow pit was once used to send over 20,000 buffalo plummeting to their death.

Ethiopian standing stones featuring remarkably preserved carvings of swords and people.

Lava stone structures possibly dating back to the 19th century may have been a stopping point for voyagers between ancient Egypt and the Mayan Civilization.

The largest burial mound in the United States holds the remains of prehistoric West Virginians.

Visitors can walk over the largest concentration of Columbian mammoths to have died from one event.

Groups of prehistoric tombs that dot the mountains of northern Oman.

More than 100 monumental tombs carved into rock are preserved at this ancient Nabataean site in the Arabian Desert.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

This sacred cavern, 400 feet deep, is home to millions of bats and an ancient burial ground.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

Marked by the hand of the explorer Henry Morton Stanley.

A set of ancient drawings in the desert of Peru that are so massive, many of them can only be fully seen from the sky.

The ruins of an ancient island city built atop a coral reef in the South Pacific are spectacular and strange enough to have inspired H.P. Lovecraft.

Ancient mysterious ruts carved in the bedrock.