This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

An underground city of salt.

Countless stories attempt to explain Poland's mysterious J-shaped trees.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

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

A memorial to the beloved brown bear that served in the Polish army during World War II.

Poland's oldest surviving university building holds a wealth of historic science instruments including some used by Copernicus.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

This sprawling concrete suburb of Kraków was designed by the Soviet Union as the model proletarian city.

At first glance, this area seems like just another city park, but the lush landscape hides a dark past.

The unsettling remnants of a torn down movie set lies nearby the ruined location of the actual Płaszów Labor Camp.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

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

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

Memorials at a Florence railway station remember the citizens who were deported from Italy and sent to extermination camps.

This Italian ski resort rose to fame when Benito Mussolini was held prisoner there and then rescued by the SS.

The sunlight passing through the opening of this huge cave system creates a magical effect.

This poignant art installation raises awareness of violence against women.

Also known as the Square Colosseum, this building is a prime example of fascist-era rationalist architecture.

The now-abandoned Fascist summer colony served a dark purpose during World War II.

The 1,000-year-old abbey is the birthplace of modern musical notation.

Ernest Hemingway was the first to sign this colorful wall covered in thousands of celebrity signatures.

This church carved into the rocks is full of enchanting stone statues.