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

Where commuters walk through remnants of an ancient Greek necropolis.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

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

The underground sanctuary of a mysterious ancient cult.

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

Rome's semi-secret peephole vista is also a former Crusader stronghold.

2300-year-old Roman road connecting the empire.

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

Erotic art covers the walls of the largest ancient pleasure palace.

Ancient snack bar of the Roman Empire re-opened.

The last bastion of Roman presence north of the Alps looms over a German town.

This Dutch statue is a monument to the fictional shrew who brought doom to the city of Stavoren.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

A radio telescope for listening to the stars, based in one of the cloudiest countries in the world.

Remarkably preserved body discovered in a peat bog.

Home to the world's oldest functioning orrery.

Pull up and have a drink at a museum filled with hundreds of years worth of shipwreck artifacts.