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

The world's oldest bookshop still in operation.

Step back in time at this 19th-century kiosk.

This giant wire frame man sculpture is crouched in contemplation.

Building Men of War and Indiamen from Holland's Golden Age.

Lombardy poplars planted to imitate the size and shape of the Cathedral of Notre-Dame de Reims.

This diner from 1930s America now resides in a small town in the Netherlands.

The final resting place of the author who gave us the Little Mermaid, the Ugly Duckling, and many more beloved fairy tales.

Hidden in plain sight, a gravestone seemingly inscribed from the future stands among the cemetery’s historic tombs.

The final resting place of one of the brightest physicists of the 20th century.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

This massive blockhead sculpture hides an entire library.

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

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The geographical center of Budapest is marked with a 10-foot-tall stylized zero.

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

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

This vast collection of smoking pipes from across the world spans centuries.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

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

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.