The modern birthplace of Irish freedom.

Amidst the bustling streets of Dublin, there is a hushed garden that is dedicated to "All those who gave their lives in the cause of Irish Freedom."

An 80-year-old plane tree is devouring an iron bench at Ireland's oldest law school.

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

The first Russian Orthodox church in the Catholic city of Rome in almost a thousand years.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

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

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

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

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

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

Birthplace of the "Cat in the Cradle" and a cluster of iconic, original windmills that let the Dutch tame the seas.

The world's first interactive human body museum also serves as a chair for a giant orange man.

A trio of red, white, and blue stones embedded in the streets of Leiden are markers of medieval territory and law.

Yup, that's a 330-foot yacht passing over the highway.

Remarkably preserved body discovered in a peat bog.

The 20-mile causeway that separates the Netherlands from the sea.

For the holidays, the tallest broadcasting tower in the Netherlands turns into one of the world's tallest Christmas trees.

This unattributed sculpture in Amsterdam is hiding in plain sight.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

A beautifully eclectic mix of architectural styles.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

A public urinal so pretty, it was declared a national monument.

Amsterdam's Red Light District leaves little to the imagination.