Copenhagen's celebrated theme park and gardens.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

An eerie, derelict amusement park in Berlin.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

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

Op-art architecture designed for happiness.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.