This outdoor observatory offers stellar views and a scale model of our solar system.

A meditative space out of a fantasy story.

A steampunk-styled three-floor factory churning out art, activism, and electronic beats.

Oldest Museum of the Netherlands is a true cabinet of curiosities.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

A unique collection of gilded age mechanical pianos.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

This cheese shop also houses a museum devoted to Dutch dairy.

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

This vast collection of smoking pipes from across the world spans centuries.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

Be it nature, art, or abandoned military architecture this eclectic German "museum" has you covered.

The largest bell in the world has been swinging high above a Cologne cathedral for almost a century.

The many—66 to be exact—faces of the German forest.

Final resting place of the humble physicist who discovered X-rays, and made the invisible visible.

This German bone house contains the remains of some 20,000 souls.

A famed artist's inspiring work of peace and tolerance.

The final resting place of the famed German pilot, the "Red Baron."

Twisted buildings adorn the banks of the Rhine river.

A church filled with the bones of hundreds of virgins martyrs—or so they say.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.