Possible relics of the ancient Roman city are hidden in this restaurant's façade.

Once in a state of dilapidation, this candy-inspired fortress is now being revived.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

A discreet little stairway on St. Nicholas Avenue leads to a quaint and unexpected cobblestone street of 19th century wooden rowhouses.

The remains of the furnace and iron works that produced the massive Hudson River Chain still stand in the woods of New York.

This once luxurious Catskills resort is now a haunting ruin.

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

Collapsing castle on the Hudson river was once the storage site of military surplus business.

An unrealized dream to wirelessly electrify the entire Earth.

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

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

What was once a trend-setting, phrase-coining icon of architectural splendor is now a rotting, forgotten hulk.

An old abandoned mining town in The Adirondacks where Theodore Roosevelt first learned of the shooting of President William McKinley.

For over 80 years, Mayan ruins stood proudly in a most unlikely location.

An abandoned asylum once on the cutting edge of lobotomies may be reborn as a Christian college.

This throwback amusement park is home to rides and unique storybook figures from the past.

These faux-cliff dwellings allow visitors to climb around on a replica archaeological site.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

Ancestral Puebloan ruins, natural arches, and box canyons abound in this seldom-visited corner of Monument Valley Navajo Tribal Park.

This historic national park is covered in the stunning ruins of red rock pueblos.