This narrow Ghent alleyway is an officially sanctioned street art tunnel.

A preposterously luxurious hotel with gold-plated iPads, Rolls Royce chauffeurs, and a staff that trains by watching "Downton Abbey."

Sitting beneath an unremarkable residential building is a museum devoted to classic Pinball.

Museum dedicated to the terror regimes of Hungary.

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

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

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

This statue of a falling man commemorates a teenage martyr of the Hungarian Revolution.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

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

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

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

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

A fascinating insight into daily life in the Eastern Bloc.

Mosaics created from 11 million cigar bands.

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

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

Museum preserving torture methods from the past.