The home of one of America's most wealthy industrialists is now a historic site that remembers a more decadent time in the country's history.

A formerly abandoned mental institute, now back in business.

An unassuming island in the middle of the Hudson that hosts campers, including Aleister Crowley.

Home to the Titanic Historical Society's collection.

This abandoned factory on the Hudson River once churned out a million bricks a week.

This mouldering abandoned mental hospital was once a center for progressive healing.

The abandoned husk of a mental institution that failed to save a Jazz Age icon still sits nearly unchanged.

Underground tunnels remain beneath this abandoned mental asylum.

Ruins of a historic medical facility sits eerily by the water.

A millionaire's abandoned swimming pool from the gilded age of one of America's most distinguished families.

Beneath the mossy overgrowth covering this once-sprawling campus lies decades of history and the secrets that come with it.

A large camera obscura, constructed entirely from digitally fabricated components.

The site of the first "historically true" UFO encounter in the U.S.

The Empire Mine is "one of the oldest, largest, deepest, longest and richest gold mines in California."

Its dark depths conceal millions of rare, delicate crystal formations.

A popular tourist cave with a dark past.

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

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

An expansive and intricately restored mansion remains from over a century ago--and so do its ghosts.

A ruined hotel with an unlucky history and an eerie present.