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

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

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

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

A collection of abandoned typographic signs from Berlin and beyond.

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

A wunderkammer of mysterious objects and stories.

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

The most visited, and possibly most controversial, museum in Germany.

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.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

The Gaudí-inspired building that was the start of Terrassenc modernism.

Two small chapels housed inside an ancient tree.

An awe-inspiring giant blue whale jaw bone stands in the center of this Dutch island.

Rich with fauna and flora, nature-lovers can walk across the sea at this UNESCO World Heritage spot.

Take a stroll through the hellish grotesques of Hieronymus Bosch in this elaborate Netherlands church.

Wonderland replication in progress by one persistent man.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

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

An eerie collection of the surviving structures from a past celebration of the future.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.