One of Amsterdam's narrowest houses is located right across the canal from its widest.

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

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

A monument to the man who almost killed Hitler.

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

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

One of downtown Berlin's last reminders of its Communist past.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

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

A surreal museum of extraordinary industrial objects.

Tiny memorials honor individual victims of the Holocaust.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

Where once there was a train station bathroom, there is now this German burger joint.

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

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

A fascinating insight into daily life in the Eastern Bloc.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

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

A mysterious shape catches the eye in this 16th-century painting.

The "Seinfeld" diner.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.