There are hidden patterns on the subway seats of some Stockholm metro cars.

Located inside Hoge Veluwe National Park, this museum began as the private collection of a prominent female art collector.

Walk along the medieval fortifications that have been protecting Tallinn since the 14th century.

These enormous, stern-faced statues greet visitors with lanterns, and sometimes costumes.

This massive, 30-foot-tall statue of the famed Scottish knight overlooks a grassy knoll.

Originally meant to hold a statue of King William IV, this support sat empty for years. Today, it hosts a rotating cast of public artwork.

This cathedral's stained-glass patchwork of psychedelic colors and shapes was put in place long before the swinging 60s.

This contemplative sculpture made out of old machine parts is meant to be the first in a series of sculptures around the world.

From Nazi chemicals to the CIA, this architectural marvel has played a fascinating role in German history.

A medieval setting reimagined into a unique art alley.

A unique sculpture calls the outside of this steakhouse home.

These blingy, baubled skeletons lie in glass boxes inside a baroque Bavarian church.

This historic funicular system combines the old with the new while offering delightful views over the surrounding valley.

After a nearly successful attempt on Hitler's life, the conspirators met their fate in the courtyard of this Berlin building.

Dancing skeletal figures pay homage to a medieval mural destroyed during World War II.

Remnants of a cone-shaped Nazi bomb shelter.

The body of at least one victim of a construction accident was left behind in the collapsed pylon, buried under tons of concrete.

These tenacious 14th-century towers defied demolition and are now a fairytale vacation rental.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.

Originally envisioned by King Ludwig II to rival Versailles, Herrenchiemsee's "New Palace" remains half-gilded for lack of funds.

Tiny memorials honor individual victims of the Holocaust.

A 12th-century fortress containing some of Berlin's oldest buildings.

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

Designed to resemble foreign architecture, this mosque-looking structure was used to pump water to a royal fountain.