These beautiful ruins deep in the Pennsylvania woods are thought to have been a ski lodge or a speakeasy, but no one really knows.

A six-story treehouse offers spectacular views of New York's Finger Lakes region.

A tradition unlike any other, this marks the site of the annual Groundhog's Day tradition.

The library of every book lover's dreams.

This semi-spooky remnant of an abandoned hotel provides fantastic views.

An allegedly haunted testament to a local businessman's desire for status, posterity, and charity.

Behold the rickety wooden glory of the world's oldest operating roller coaster.

The graffitied ruins stand hidden within the Pennsylvania woods.

This eerily well-preserved coal town was saved from destruction by a Sean Connery movie.

A train station that was abandoned by the coal industry and was later converted into a cocktail bar.

This extraordinary Depression-era expenditure was modeled after a postcard of a Mediterranean hotel.

Buildings that dynamite couldn't bring down were abandoned because of bathroom issues.

When the Austin Dam failed it destroyed much of Austin...and then it failed again.

A mine fire has been burning under the deserted town since 1962, but this church is still going strong.

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

This lush forest valley was once mined for lumber to the extent that it was once nicknamed "The Pennsylvania Desert."

A burnt-out motel with priceless Native American artwork in the basement, redeveloped into apartments.

A wacky, UFO-shaped house in a suburban neighborhood.

An abandoned amusement park based on the popular 1940s Red Ryder comic strip.

A futuristic temple of light uses prisms and rainbows to create an atmosphere of peace.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

The fading, forgotten remains of a once bright and booming factory.

San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.

You might know it as the Overlook Hotel, but the inside is not going to be familiar.