This one-time health resort was used by aristocrats around the world.

This lakeside bunker complex in Mamerki, Poland, housed the Supreme Military Command of Nazi Germany during World War II.

Walk inside a half mile long crevice right outside the town of Garmisch Partenkirchen.

A small but immensely extravagant palace built by the "Night King."

A unique bridge with an equally unique view.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

The fairy tale castle of the "fairy-tale king."

The footprint of a frustrated devil in Munich's Cathedral.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

Eighty million natural history specimens call this gargantuan museum home.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

A fairytale Gothic castle steeped in Nazi treasure conspiracy theories.

This towering church is home to a world-famous organ and a treasure trove of medieval art.

Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.

An artificial date palm stands as a memorial to Warsaw's Jewish community.

In the summer, the area around this sculpture transforms into a vibrant concert venue.

This fairytale medieval church in Poland originally spent centuries in Norway.

The Polish capital has had a deep connection to its guardian mermaid for almost a millennium now.

This fairytale inspired, warped building houses restaurants, shops, and a radio station.

A striking public sculpture representing the period of martial law in Communist Poland.

A statue honors the children who fought Nazis in Poland.

Museum dedicated to "the man who moved the Earth."