The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

Scattered throughout London are ancient remnants of the city's former bounding wall.

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

In Florence's great Duomo, a 26 foot fresco honors a mercenary famous for attacking Florence.

More than 450 years ago, an Italian nun became the first woman to paint the iconic subject.

This Roman statue is missing a limb from when the Venetians stole it from Constantinople during the Crusades.

The walls and streets of the ancient city are peppered with penises.

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

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

Ancient snack bar of the Roman Empire re-opened.

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

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

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

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

A massive marble foot is tucked away in a small alley near the Pantheon.

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

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

The Los Angeles flood disaster that took 400 lives and ended the career of William Mulholland.

A remote crossroads honoring a fallen talent.

An antique store houses the last operational diner from the defunct department store chain.