This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

Caves famous for the dragon-slaying saint who lived there.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

A nearly 500-year-old sculpture depicts a man eating a sack of babies, and no one is sure why.

The largest known open fault in the United States is basically a giant natural refrigerator.

Built on the remains of one the Incas’ most important gathering spots, this square keeps the spirit of a fallen empire alive.

This glacier interpretation center houses the world’s only bar made completely from glacial ice.

It may take some time to locate, but it's sure to warm even a heart of stone.

A series of playful yellow penguins share a serious message about the environment.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

The world-record holder for the longest bridge stretching continuously over water.

A backdoor to Machu Picchu that only the most foolhardy infiltrator would attempt to breach.

This geometric feat is a testament to the Incas' mesmerizing architectural abilities.

Once the site of a Native American harvest festival, this humble clearing later played an invaluable role in the birth of jazz.

This distinctive Crescent City tradition dates back to the days of horse-drawn carriages.

Situated on a sacred Inca site, this 16th-century cathedral took nearly 100 years to build.

Known as the "Valley of the Moon," this Jordanian wadi is one of the most amazing desertscapes on Earth.

At this Arctic outpost, get to know members of the indigenous Sámi community and meet their herds.

Terrifically morbid cemetary and site of famous Paracelsus' grave.

A tree planted by Marie Curie is treasured by the Radium institute that she set up.

An Inca spa, military outpost or maybe… both?

A plaque marks the spot where the saint was shoved off the Charles Bridge and into the river.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

This abandoned factory on the Hudson River once churned out a million bricks a week.