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

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

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

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

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

Cold war icon and onetime "hole" in the iron curtain.

A 'living museum' in Leiden, the oldest of its kind in the Netherlands.

Hidden within a Netherlands crater is a stone bed that lets those who lie in it see the sky as a curved surface.

A miniature city, once ruled by the Queen of the Netherlands.

The largest 19th century panorama in the world still in-situ.