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

Tiny memorials honor individual victims of the Holocaust.

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.

Berlin's old airport.

A 12th-century fortress containing some of Berlin's oldest buildings.

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

The most visited, and possibly most controversial, museum in Germany.

A memorial to the nearly 10,000 American soldiers laid to rest on the beaches of Normandy during WWII.

A daring D-Day assault by U.S. Army Rangers is commemorated atop the high cliffs of this strategic point.

Remains of the artificial harbours invented for the Allied invasion of Normandy can still be seen at sea.

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

A magnificent collection of imperial armor and weaponry.

The housing complex served as an anti-fascist fortress during the Austrian Civil War.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

This series of Baroque passageways in Vienna's cultural center mix old architecture with modern art.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

An exquisite Baroque church in Vienna's old town.

The Habsburgs' royal collections of art and wonders.

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

Apartment complexes built into huge repurposed natural gas tanks.

A silly medieval mural preserved on the side of a Viennese house.

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