Cursed swimming pool left abandoned is now a favorite of filmmakers and ghost hunters.

Haunted tuberculosis hospital built by the patients.

Nothing says indulgence like a 1,500-pound chocolate castle.

An abandoned theme park with a strange and tumultuous past.

An abandoned Victorian-era amusement park is rusting away amidst luxury houses.

This abandoned amusement park was built on a site with a dark history.

The singular ruins of a mysterious lost city.

An elaborate Mayan city shrouded in alien conspiracy revealed the tomb of Pacal the Great.

An underwater road considered a possible Atlantis location.

The only geyser in the state of Pennsylvania is caused by pressure from an abandoned coal mine outside of the ghost town Centralia.

A modern ghost town whose inhabitants were driven away by the growth of nuclear power.

Spectacular mineral formations fill these caves, which have been used for everything from smoking meat to stashing illicit liquor.

This ancient structure was built by a mysterious civilization that was largely destroyed by a volcanic eruption.

Beyond the usual stories that attend old prisons, this one has deep bloody undercurrents.

World's first "penitentiary," meant to be humane, drove men insane.

One of the best places to dig—some say on the planet—for six different types of chalcedony.

An overgrown garden stands as a grim marker of an unrealized dream.

A labor of love built by local hang-gliding enthusiasts, this ideal launch spot was outlawed by the authorities and has since been largely abandoned.

A rock maze opens up to a panoramic viewpoint at an abandoned mine full of ghost stories.

This abandoned sea fort has become an accidental bird sanctuary.

There's a crumbling old mansion inside the Smithsonian National Zoo.

An abandoned stretch of highway, deteriorating next to the operational one.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

An eccentric company offers eccentric millionaires the opportunity to have spaceflight-related experiences.