The oldest cemetery of modern-day Athens blends the modern and ancient worlds.

Where commuters walk through remnants of an ancient Greek necropolis.

An ancient octagonal weather station named for the eight Greek gods of wind.

A quirky bookstore hidden beneath a sea of whitewashed Greek villas.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

Reminders of the Battle of Berlin still scar the railway.

A replica of the Liberty Bell rang daily from West Berlin's City Hall throughout the Cold War.

After a nearly successful attempt on Hitler's life, the conspirators met their fate in the courtyard of this Berlin building.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

A restaurant and observation deck built in a unique broadcasting antenna.

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.

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

The celebrated eyesore created by starry-eyed sweethearts.

The video game-themed street art first popped up in the French city.

This triumphal arch celebrating the Sun King's conquest of Lille is a masterpiece of military architecture.

Tables of secondhand books fill the inner courtyard of this 17th-century stock exchange.

What looks like a normal building is really a hollow facade hiding a subway vent.

A 400-year-old church covered floor to ceiling in ex-voto offerings from the faithful.

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

A series of abstract, silly sculptures represent the works of a great modern classical composer.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

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

19th century pendulum and a clock restored by a rogue group of guerilla artists.

A fortress off the West coast of Portugal that dates back to 1502.