The medieval institution is home to the precious treasure stolen in World War II in one of the greatest art thefts of the 20th century.

Garden dedicated to native carnivorous plants and site of huge flytrap heist.

An ancient monastery, a locked room, and a mysterious book heist.

A large measuring stick marks the lowest point of a country that is partially under sea level.

This risqué sculpture, based on a Hans Christian Andersen fairy tale, caused outrage 35 years after it was erected.

The second-longest continuous wall on the planet protects a hidden secret in the deserts of India.

In the remote high desert of New Mexico, a strange array of poles beckon fury from above.

Small caves once used as a hiding place for some of those accused during the Salem Witch Trials.

Gladiators battle and chariots race daily in the ruins of a once-great Roman city.

Mosaics, storks, and brothels—this ancient city has it all.

An ancient city hidden in the heart of the Sierra Nevada mountains.

Huge stone depressions which may have acted as an Incan agricultural experiment.

This hunter-gatherer architecture is believed to be the oldest religious complex known.

In what is rumored to be an intentional act of spite, this memorial almost completely obscures the nearby grave of a senior officer.

Underneath the historic center of Mexico City, the remains of a temple dedicated to the Aztec god of the wind.

This black cat was actually designed to ward off bad luck.

With a floor made of thick glass, this observation deck offers a full view of Sunwapta Valley's mountains and rivers.

This ruined castle is said to be the legendary keep of a Viking princess.

Daikon radishes are offered to the Japanese Buddhist counterpart of the Hindu god Ganesha at this historic hilltop temple.

The final resting place for the famed creator and narrator of "The Twilight Zone."

This retro diner claims to be the birthplace of poutine.

Built in the 1920s, this co-op in the Bronx feels more like an Italian villa than a typical New York apartment building.

These towering cliffs crystalize each winter, forming sheer walls of ice that are open for climbing.

Isak Heartstone, a 15-foot wooden troll made out of recycled materials.