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

An abandoned Byzantine fortress and notorious prison.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

This still-celebrated home was a radical architectural experiment in 3D De Stijl.

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

The birthplace of most all of Europe's space missions is here on the Dutch coast.

The works of poetry's biggest names grace the walls of the city of Leiden, all carefully painted by hand.

Devious political maneuvering and four ancient, working telescopes are central to the world's second-oldest observatory.

This historic Dutch newspaper building is covered with media-themed details—and one unrelated oddity.

A lecture hall sink once used by Einstein and other noted physicists is now regarded as a strange science relic.

Rotterdammers' dirty minds gave this santa a dirty nickname and cursed it to a life of wandering.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.

The ancient tomb acts as a calendar that keeps perfect time.

This permanent collection of preserved bodies taken from Irish bogs is one of the leading authorities on such morbid mummies.

One of Ireland's most infamous prisons for rebels including men, women and children.

Locals spent years successfully fighting to save this beloved Brutalist behemoth from demolition.

One of the oldest amusement rides in existence was a huge disappointment to its creator.

A typographic tribute to the many comedic greats who make Great Britain laugh.

80 years of the Battle of Peasholm on a small English lake.

The National Railway Museum in York is the largest railway museum in the world, attracting almost 1 million visitors per year.

One of the last remnants of the Bessemer process that revolutionized steel production during the industrial age.