This historic "City of the Dead" lies prominently in the center of New Orleans' famous Garden District.

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

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

The oldest cemetery in New Orleans, resting peacefully for over 200 years now.

Just a few miles from downtown Atlanta is a trail covered in a crazy collection of outsider art.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

This is the oldest Roman-made bridge in the city still existing in its original state.

Legend has it that this bronze orb, which sat atop an ancient Egyptian obelisk, once held the ashes of Julius Caesar.

An ancient Roman temple first dedicated to an emperor's wife is now a church.

Stare out over the lagoon and beyond from this 10th-century campanile on the island where the city of Venice began.

This large, circular tomb is the final resting place of the first emperor of Rome.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

A slightly creepy gallery of plaster cast models in the same museum as Michelangelo's David.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

A dismembered holy head stares out from her beautiful reliquary at the St. Dominic Basilica.

Medieval torture techniques with a modern conscience.

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

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

Go inside to really appreciate this 500-year-old technological masterpiece.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.