1920's reinforced concrete church by architect Auguste Perret changes the face of modern design.

This was once the center of the Birdman cult, and is now a World Heritage Site.

Rivers of cattle blood gone, a strange Escheresque building remains, the last of its kind.

A lush desert oasis in the shape of a narrow crescent.

The famous winding walk at Chartres is surrounded in mystery and myth.

Yale University's home for rare works, including the mysterious Voynich Manuscript.

Shocking dioramas of human torture, meant to promote human rights awareness.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

This antique prison is a tourist attraction with a sordid past.

Remote, volcanic island that Darwin, Hooker, and the Royal Navy shaped into a thriving, artificial ecosystem.

A mysterious castle built as a monument to lost love.

This mountain's identity is stuck somewhere between a nightmare and a scenic tourist attraction.

This beautiful "lagoon" is actually a toxic soup filled with cars, carcasses, and trash. When warnings couldn't stop people from going for a dip, the town dyed it black.

A gruesome memorial for those lost in this area during the Khmer Rouge genocide.

Costumed elves and mountain bikers co-exist peacefully at this abandoned Christmas-themed adventure park.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

This "zoo" is a cross between a junkyard and a sculpture garden, featuring animals you won't see anywhere else.

The antique barns in Cameron are not painted with your grandfather's Mail Pouch Tobacco murals.

These eclectic homes nestled into the cliffs of a Caribbean island were built entirely from scavenged materials.

These Nubian pyramids are strange and unique, even by pyramid standards.

The one-time stronghold of the noble Douglas family, now home to ghost sightings and nesting birds.

Not one, not two, but three natural bridges remain in this captivating spot post-sinkhole.

A peace symbol in Northern Ireland is among the world's largest hedge mazes.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.