A beloved horticultural oasis on the grounds of a wealthy family's former estate.

Enchanting gardens surround a derelict mansion, all hidden in plain sight behind a stone wall.

Descendants of this colonial Pennsylvania family still travel from far and wide to visit the 300-year-old home of their Quaker ancestors.

The once abandoned ruins of a Victorian beachside amusement park are now back in working order.

The remnants of a 19th-century ironmaking complex hidden in the woods of Connecticut.

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

An extraordinary collection of vampire-themed antiques lurks on the second floor of a store.

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

This demolished goliath of American industry once loomed over the depressed town it once made thrive.

The headquarters of the Fraternitas Rosae Crucis, complete with Rosicrucian pyramids, all in the Pennsylvania woods.

Where America's first doomsday cult awaited the end of the world.

Vacant Beaux-Arts buildings that serve as reminders of a beach town’s glory days.

This hospital fell into ruins after failing to act as the advocate for the mentally ill it was designed to be.

Rusting away on the edge of New Jersey are the remains of a Cold War missile launch site.

The remains of a century-old mansion that met a fiery demise years after it was deserted.

In the woods of New Jersey lie the ruins of a munitions village abandoned after World War I and the remnants of a 1920s wooden racetrack.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

This historic iron-working village is now a ghost town so immaculate that it looks as though it was recently built.

This factory made "health corsets" that were a step towards liberating women's bodies.

An abandoned Victorian-era mill in the middle of modern Manchester.

A miniature village lies nearly forgotten in the forest by the side of a major highway.

An Escher-inspired library dedicated to the wonders of the human mind, yet closed to the public.

Yale University's home for rare works, including the mysterious Voynich Manuscript.

A religious-themed park filled with folk art to bring biblical stories to life that fell into disrepair and now being restored.