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

An abandoned NSA listening post on Berlin's "Devil's Mountain."

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

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

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 slice of central Asia in the middle of Berlin.

Started as a kitchen garden, now the second largest botanical garden in the world.

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

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

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

The final resting place of two (or three) presidents, one vampire, and 18,000 Confederate soldiers.

A Nazi concentration camp and Anne Frank's place of death.

A mouldering Colombian bull ring stands as a reminder of the country's complicated relationship with a brutal sport.

An inspired museum dedicated to the patron saint of enslaved people, inside the cloisters where he lived and died.

Hidden amid the tropical forest in the Caribbean Sea are the decaying ruins of the Cocaine King's luxurious island party home.

The colonial city's social history is reflected in its fanciful door knockers.