The old observatory in Copenhagen has a spiral corridor used as a racetrack.

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

"Girl in a Wetsuit" is what happens when a sculptor has to find a way around a 100 year old copyright.

A pixel art killer whale is frozen mid-leap in this Vancouver square.

A working steam clock, one of only a few in the world, located in Vancouver's Victorian Gastown.

Cold war icon and onetime "hole" in the iron curtain.

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.

The most visited, and possibly most controversial, museum in Germany.

A unique underground structure dating back to the 1st century BC.

Even France's favorite aquatic son Jacques Cousteau, couldn't get to the bottom of it.

The mental institution where Van Gogh created some of his most famous work now allows guests to walk in the artist's footsteps.

A historic observatory precariously perched at the "Top of Europe."

A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

The largest preserved walking dragline excavator in Western Europe.

Astonishing rock formations dot the Brimham Moor landscape.

One of the oldest and certainly best preserved Cistercian abbeys still in existence.

This lovely little burbling creek is actually a deadly waterway that has dragged down everyone who ever set foot in it.

WWII artifacts, including the building itself.

Once thought to be the mysterious work of a witchy prophetess, a well with unusual properties turns objects into "stone".

A century-old tradition has culminated in a small but singular collection of feline effigies.

This disused Cold War bunker has been restored to all of its early 60s glory.

The National Railway Museum in York is the largest railway museum in the world, attracting almost 1 million visitors per year.

Famously misunderstood wonder of the ancient world