The cave holds a spectacular array of stalactites and stalagmites, including one shaped like a giant human heart.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the 20th century.

The French leader's hat sits in a glass case at the oldest restaurant in Paris.

For more than a century, Parisians have come for affordable dishes in a grand converted train station.

A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

A giant silver apple a day keeps the perils of capitalism away.

A phantasmagoric tomb honors a Belgian artist-scientist's contributions to the world of spooky entertainment.

Shop at the 200-year-old store where Julia Child stocked up on copper cookware.

Order a boozy baba au rhum at the oldest patisserie in Paris.

Offal and flawless onion soup are on the menu at this restaurant that once catered to the workers of Les Halles.

Marvel at the opulent Art Nouveau interior while dining on dirt-cheap French classics.

This oddly shaped boulder in Paris is rumored to be cursed.

Montmartre's sole surviving windmill became an iconic landmark for 19th-century painters, artists, and bohemians.

Marie Antoinette and Napoleon Bonaparte were fans of this 200-year-old French chocolatier.

The bones of the Biblical Magi traveled to Constantinople and Milan before landing in their current home inside an elaborate golden reliquary in the Cologne Cathedral.

Abandoned railway line circling the city of Paris.

The location of this small park was once the site of an infamous public morgue.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

The remains of this 2nd-century Roman temple are incorporated into a modern building.

A monumental fountain in Rome features a large statue of Moses that has been criticized for centuries.

This Italian stadium makes liberal use of fascist statuary to evoke classical sporting arenas.

Also known as the Square Colosseum, this building is a prime example of fascist-era rationalist architecture.

This gallery commissioned by Cardinal Spada is known for its magnificent optical illusion.

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