Go inside to really appreciate this 500-year-old technological masterpiece.

What looks like a crashed Zeppelin is actually a bright, airy reading room perched atop a modern museum.

This ruined folly was originally built to honor a failed American state that would have become "Westsylvania."

This cubist Vienna church building looks like some sort of alien stonehenge.

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

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

This museum promotes informed contraception by documenting its often secret past.

The topiary maze at the Habsburg hunting lodge.

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

A spherical "micro-nation" in the heart of Vienna.

This former insane asylum now holds a pathological anatomy museum.

King Ludwig I's collection of beautiful women.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

"In the Dark" Restaurant in Paris offers dinner in complete darkness.

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

A slice of central Asia in the middle of Berlin.

Gardens representing parts of Asia, Europe, and the Mid East are tucked away among the Soviet-style buildings in East Berlin.

A state-of-the-art medical facility from the Imperial era is now a derelict ruin.

When German-Iraqi relations broke down, this embassy was vacated post haste.

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

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

This conical hill was built as a testing ground for an engineer known as the Glider King.

A fascinating insight into daily life in the Eastern Bloc.