Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

The attic of a four-century-old canal house hides a clandestine church.

The history and future of cannabis.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

Cat art as far as the eye can see.

A floating cat sanctuary on an Amsterdam canal.

A curious collection dedicated to human and animal anatomy and pathology.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

The final resting place of many of Germany's most famous communists.

Berlin's beloved bear is immortalized at the Museum für Naturkunde.

A 12th-century fortress containing some of Berlin's oldest buildings.

Beneath the impressive baroque cathedral that rises from the center of Berlin lies the largest collection of Prussian royals in the world.

Puppet theater and museum holding a collection of more than 300.

Home to 10,000 medical specimens including the remains of Rudolf Virchow's extensive collection of pathological specimens.

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

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

Berlin's natural history museum houses the world's largest mounted dinosaur and the late beloved polar bear Knut.

From toys to kettles to scientific instruments, this German museum celebrates the beauty of 20th century design.

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.

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

A surreal museum of extraordinary industrial objects.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

An eerie, derelict amusement park in Berlin.