The last four extravagant street signs of London's historic banking street.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A whimsical bridge adorned with decorative dragons.

Bridge that died in war and was resurected.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

This fishing contraption sits on top of a series of spindly wooden stilts.

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.

The remains of an ancient Roman city are hidden underneath Bologna's beautiful public library.

A striking memorial recalls thousands of Bolognese men and women killed fighting fascists in World War II.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

A large statue of Pope Gregory XIII in Bologna was disguised as Saint Petronius to avoid destruction.

A small window on Via Piella offers a lovely and rare peek at Bologna's lost canals.

A memorial to the nearly 10,000 American soldiers laid to rest on the beaches of Normandy during WWII.

The world's largest reflecting pool is just two centimeters deep.

Massive puppet-automaton machines created by French artist collective Machines de l’Ile.

Historic medieval fortified city in southwest France.

Ancient paintings known as the "Sistine Chapel of Cave Art."

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

People have been living in the cave houses on this Italian hillside since the Neolithic era.

A long-buried ancient ruin unearthed right in the middle of the city.

Dramatic sea stacks adorn the coast of this small village on the Adriatic coast.

Geometry and mystery come together in an epic show of octagonal masonry.