A monument to the three wars that led to German unification towers within a Berlin traffic circle.

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

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

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

Metro station with a claim to rock n' roll fame.

A traditional U-Bahn station in Berlin gets a string of rather untraditional benches.

Cold war icon and onetime "hole" in the iron curtain.

The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

The world's oldest bookshop still in operation.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

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

The walls of Germany's Parliament still show the scars of the Red Army takeover in World War II.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

The former headquarters of history's oldest megacorporation.

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

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

The house that took a plunge into the facade of a museum.

An exquisite Baroque church in Vienna's old town.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

Baroque celebration of the end of the Great Plague of Vienna.