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

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

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

France's most famous cemetery, with some of its most curious tombs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The zoological collection at the Hessisches Landesmuseum hosts some of the world's oldest habitat dioramas.

This monument to those fallen in the World Wars is accompanied by a U-boat that Germany bought for a Deutsche Mark.

1898 German railroad depot museum with working engines, steam train excursions, and hands-on displays.

Fantastic views and thousands of love locks.

Hamburg's first legal sex work is relegated to a gated street that still does not allow pedestrian women.

Sitting in the basement of a castle, the largest wine barrel in the world is bigger than most apartments.

This historic funicular system combines the old with the new while offering delightful views over the surrounding valley.

It's good luck to be mocked by this monkey.

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

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

The "Prussian Versailles" that is as glorious today as when it was built.

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.

A quaint Russian village in the middle of a German metropolis.

Berlin's old airport.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

A fascinating insight into daily life in the Eastern Bloc.

Art and a pun, all in one.

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

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.