A natural gas leak provides a flickering flame beneath a waterfall.

A once grand hotel is being retaken by the wilderness it once capitalized on.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

Nondescript elevator doors open to reveal a stunning, surreal world.

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

Sniff the Titan Arum's rotting flesh.

More gold than anywhere else, ever.

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

Designed by Horace Trumbauer in 1893, this Gothic-style castle is now a home for academics.

Memorializing an American tragedy of massive proportions.

"Where the ducks walk on fish."

The site of the little-known Pennsylvania battle that sparked the Seven Years' War.

A planned settlement in Pennsylvania once housed the aristocratic refugees of the French Revolution.

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

This historic old movie house was the scene of one of the Blob's most iconic attacks.

This dramatic rail curve was once the target of a failed Nazi attack.

A soon-to-be-forgotten roadside spectacle loaded with local lore.

Journey through a collection of over 35,000 Halloween items from all generations.

A quirky collection of outsider art made from automobile parts.

Pennsylvania's highest point is spotted with boulders which were pushed to the surface by nothing but cold.