The prototype for all Nazi concentration camps.

A formerly glacier-tipped volcano that inspired none other than Jules Verne.

Erotic art covers the walls of the largest ancient pleasure palace.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

This encrypted monolith protected a secret of Norse mythology by hiding in a church wall for over a millennium.

A giant white horse drawn on an English hillside may not have been intended to be a horse at all.

Largest lake in Great Britain measured by surface area.

Charles Babbage's proto-computer, painstakingly brought to life.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

One part local history, 99 parts gruesome haunted house.

Copenhagen's celebrated theme park and gardens.

Climb inside an iron crystal magnified 165 billion times its normal size.

The ancient tomb acts as a calendar that keeps perfect time.

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

Relive a Polish uprising via an enormous, century-old cyclorama.

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

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.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

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

A former palace transformed into a mausoleum for North Korea's supreme leaders.