The original home of the Lego has a huge amusement park dedicated to the iconic plastic toy.

Once designed as the entrance to Buckingham Palace, this structure was later relocated and stands as a victory arch.

The plunge pool is a surviving relic of a rowdy royal residence.

An architectural oddity hides in plain sight on this iconic London bridge.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

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

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

The Metropolitan Police refurbished the blue box (perhaps not coincidentally) the same year "Doctor Who" returned to TV screens.

After nearly 60 years, there's still a bear at Paddington Station looking for help.

Catacombs turned marketplace.

Eighty million natural history specimens call this gargantuan museum home.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

This public toilet built in the famous Amsterdam School architectural style is a Dutch national monument.

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

Famously misunderstood wonder of the ancient world

The celebrated eyesore created by starry-eyed sweethearts.

This bridge was constructed from the rubble of the infamous Bastille.

The curious underground history of keeping Paris clean.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

Germany's longest suspension rope bridge.

This 600-year-old home seems to defy physics.