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

One of downtown Berlin's last reminders of its Communist past.

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

A fascinating insight into daily life in the Eastern Bloc.

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

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

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

A simple plaque on the facade is the only reminder that the treaty ending the American Revolution was signed inside.

Former hunting lodge of a duke who was an avid collector of impressionist works.

A French artist's vague warning hangs over Belleville.

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

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

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

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

Natural history museum celebrating biodiversity with a parade of taxidermy animals.

In the best of all possible worlds, everyone will get a chance to see this statue in which Voltaire's heart is interred.

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.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

The first green space constructed on an elevated viaduct.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

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

This museum houses an imposing skeleton army comprised of creatures great and small.

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