Haunted tuberculosis hospital built by the patients.

Secret Manor, a house full of legends, the least of which is the haunting of long-deceased ladies of pleasure.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

An unfinished complex built for children from around the world sits abandoned on the Black Sea coastline.

An abandoned 1920s school with a mysterious history.

This empty Detroit high school was too expensive to maintain or destroy.

This Detroit ruin was once a gothic bastion of its community, but now it stands as a haunting ruin.

Abandoned concert venue legendary for its rock counterculture.

A painted-over wall in Detroit originally built to segregate a black community from an adjacent white development.

Weighing 30,000 pounds, this monument represents Detroit's first industrial era.

What was once the largest NFL stadium.

A winding, blood-red tunnel of hardened lava navigable by foot.

To literally keep their waste out of their own backyards, the citizens of this English city built an impressive sewer system that is still in use today.

This concept building is the UK's first attempt at making a permanent structure of nothing but trash.

In Twickenham sits a small whitewashed castle that inspired Mary Shelley's 'Frankenstein.'

No one knows who created the statues or if they are arranged properly—let alone the artwork's real name.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

This striking public art installation is suspended above a public park, designed to gently move in the breeze.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

A self-built castle made by a mysterious man.

An abandoned facility that has become a place of ritualistic satanic worship, or so rumor has it.

Abandoned railway line circling the city of Paris.

On the Oregon coast there is a natural hole that seems to be draining the sea.

This frequently-photographed waterfall takes only a short hike to visit.