A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

The final resting place for the remains of 143 Habsburg royalty.

The beautiful baroque library of the Hapsburg empire.

A slice of central Asia in the middle of Berlin.

Come stay at a live-in art installation.

An old department store turned Nazi prison turned artist commune.

The music is over at the Ballhaus Riviera Ballroom, but the ballroom remains in haunting disrepair.

An abandoned swimming pool decays on the outskirts of Berlin.

The original burial place of this preeminent 18th-century Jewish philosopher was razed by the Nazis.

This sprawling Jewish cemetery is one of the largest in Europe.

Berliners converted a bombed-out, disused lot into a community-run urban farm with its own cafe and bar.

Named after a militant urban guerilla, this famous former squat is a graffiti-covered stronghold of leftist culture.

What started as a tongue-in-cheek shrine is now a full-blown museum celebrating "The Hoff" and his longtime love affair with Berlin.

A wunderkammer of mysterious objects and stories.

A surreal statue honoring Prague's favorite literary son.

Macabre astrological automaton clock dating to the late 1400s.

In the middle of a Vienna square, Roman ruins dating back some 2,000 years are on display.

A patriotic medieval knight in driven-nail armor raised money for widows and orphans of WWI.

Museum devoted to the artificial language of Esperanto.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

Pop culture has helped to keep this iconic British building from being destroyed.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.