These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

An ancient knight and a symbol of the city's freedom.

The final resting place of the great navigator, or maybe his brother.

The world's largest wooden structure.

At the time of its completion, it was the tallest dam in the world.

There are eight natural springs around town, each with a slightly different taste.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

Op-art architecture designed for happiness.

A classic gold rush hotel can be expected to pick up some ghosts along the way, and the Golden North is no exception.

A rare chance to get up close and personal with a 13-mile ribbon of ice near downtown Juneau.

This historic collection of Native Alaskan artifacts was resurrected through a partnership between the WPA and tribal artisans.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

This Colorado hiking trail provides a small gold mine of abandoned gold mines.

Ironically this massive termite is the mascot for a company that is acclaimed for killing his kind.

The site of a concentration camp where inmates were made to take part in one of the largest counterfeiting operations in history is now hauntingly empty.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

The celebrated eyesore created by starry-eyed sweethearts.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

Eighty million natural history specimens call this gargantuan museum home.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.