Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

A 30-acre garden inspired by the principles of modern physics.

"World's largest scrap metal sculpture" stands in an outdoor sculpture garden in the middle of Wisconsin.

Centuries-old bridges grown from tangled roots.

An ethereal glowing blue ocean cave in Croatia.

An Aztec snake god has taken the material form of an apartment complex.

A gargantuan crystal kingdom.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

Keshwa chaca, among the last handwoven Incan bridges, crosses Apurimac Canyon in Peru.

Site of a former hidden treehouse in New Orleans.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

A trash dump made beautiful by nature's power.

The ghostly remains of an accidental sea.

The largest of London's subterranean rivers and once a mad, bad center of London life.

This structure among the trees was the result of divine inspiration.

A battle between nature and architecture in the Cambodian jungle.

Eighteen miniature death-scene dioramas.

The world's largest collection of witchcraft regalia.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

The fairy tale castle of the "fairy-tale king."

A 16th-century horror show built in a lovely Italian garden.

The world's highest and most dangerous infinity pool lies at the precipice of Victoria Falls.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.