This Polish cave has housed a dragon, a brothel, and an enduring legend.

Real bones which are said to have belonged to a Polish dragon.

This watchtower once presided over the Berlin Wall.

Metro station with a claim to rock n' roll fame.

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

The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

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

A fascinating insight into daily life in the Eastern Bloc.

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

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

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

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

In this quiet park a rendition of a classic painting graces the outside of a charming restroom.

One lonely, modern pyramid has gone from corporate think tank to deserted boondoggle.

Where most of the world's flypaper was made.

These sprawling mines once served as a source of plaster and today serve as a storage facility.

Outside Grand Valley State University, you'll find a bench upon which many were said to have sat according to the fictional Kcymaerxthaere, waiting for a guide of time.

The origin of the Nixon tapes is rooted in technological incompetence as much as secrecy.

An angular maze of concrete in Grand Rapids acts both as public art and as a staircase for fish traveling upstream.

In Grand Rapids, Michigan, a marker honors the creation story of a proud fictional culture.

The museum moved on, but the diorama remain.

At HopCat, a marker honors fictional creatures with the ability to travel the missing dimensions of Kcymaerxthaere.

At Fountain and Division, in the shadow of Kendall College of Art and Design, lays the story of a fictional culture whose political system was used under license and who finally rebelled.

An enormous park-like oasis, full of famous Chicagoans’ graves.