A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

This 29-ton granite ball spins around at the slightest touch thanks to a scientific phenomenon.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

The hallucinogenic center of the ancient world.

Pompeii's less famous neighbor is still revealing her secrets.

Ancient snack bar of the Roman Empire re-opened.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

A sulfuric hellscape in southern Italy.

Italy's third-largest Roman arena gives a peek into the underground operations beneath the ancient spectacles.

Virgil's many-mouthed gateway to the underworld.

A submerged archeological park still holds the wonders of a Roman Sodom.

A tree that defies gravity grows in an ancient ruin.

The Roman Emperor's lost summer home and grotto full of enormous sculptures sit along the Italian seashore.

This Arabesque Italian castle was built with a primitive, if ingenious, air-conditioning system.

Thousands of well-dressed mummies below a monastery.

The world's most active stratovolcano is almost always erupting.

Italian cave with exceptional acoustics and an unsavory history.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

Caligula's colossal pleasure ships, discovered by Mussolini only to be lost in flames.

Largest necropolis in the Mediterranean.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

2300-year-old Roman road connecting the empire.