These disused steel furnaces are now haunting ruins that may one day be a national park.

A once crucial portion of the Long Island railroad still lays abandoned, waiting to be turned into an urban park.

This tiny New Jersey village has lived many lives but seems determined to remain a ghost town.

Run by a eugenics advocate, this aging institution conducted secret radiation experiments sponsored by Quaker Oats.

Built by the inventor of the radio, this abandoned hotel has housed early radio employees, military men, and a dangerous cult.

Decades after testing the polio vaccine on unwitting patients, this historic mental hospital sits in ruin.

The "Fun Spot of the Desert" is now a haunting ruin, and a reminder that putting a water park in a desert is a bad idea.

An abandoned subway tunnel that could have reinvigorated Staten Island still lies somewhere beneath this Brooklyn park.

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

The graffiti-covered remnants of a former triangulation station are balanced precariously on this California peak.

This abandoned Poconos resort is haunted by a history of kitschy romance and a violent fugitive.

This huge, disused viaduct is now a crumbling concrete underworld of covered in years of graffiti.

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

This abandoned ironworks was once the most important military supplier in America.

These World War I shooting range tunnels are now haunted halls of underground graffiti accessed through the roots of a tree.

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

This old mining town, deep in the California desert, has a year-round population of one.

After hundreds of years of settlement, this once-bustling fishing village sunk into the Chesapeake Bay.

Once a place of peaceful repose, this sanitarium now faces an uncertain future.

Crumbling ruins mark the site of a couple's grisly murder in the woods.

Collection of trolley cars in the woods represent one man's attempt to preserve transportation history.

A former connection to City Island, it has been abandoned since the 1930s.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

This former theme park in New York's Adirondack Mountains fell into ruin before being resurrected as a state-run campground