The first declared National Monument in the United States.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

The final resting place of New Orleans' most famous voodoo priestess.

A snapshot of the city's fascinating voodoo culture.

Most-visited and most-photographed slot canyon in the American Southwest.

This huge clock made of flowers and simple machinery was once used a political weapon.

This boulder stays on its mountain thanks to a huge chain and on the map due to local legend.

Eight rare Corvettes are swallowed up by a sinkhole in Kentucky's National Corvette Museum.

Moonbows over Kentucky.

The world's longest known cave system.

Prehistoric animals decorate this popular outdoor park.

The site of Austria's biggest concentration camp now honors its victims.

A magnificent collection of imperial armor and weaponry.

An ornate private entrance to the Vienna subway built specifically for the emperor.

The world's largest historic armory was established by independent citizens to defend themselves from the wars of larger forces.

A rooftop restaurant hides in plain sight atop Vienna's Palace of Justice.

The world's oldest known salt mine.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

American soldiers discovered Europe's best one-liner at the end of World War II.

Resting in the middle of an Austrian river, this sci-fi "island" lets people cross in neon style.

This series of Baroque passageways in Vienna's cultural center mix old architecture with modern art.

Museum devoted to the artificial language of Esperanto.

Ride a dragon train into a world of dwarves.

The solemn exterior conceals an opulent interior of this 17th century church.