Steepest flood safety railway in the entire world.

Memorializing an American tragedy of massive proportions.

A hidden piece of Altoona's railroad history in a long-forgotten abandoned town.

Despite violent work crews and massive delays this abandoned canal tunnel was built to last into the modern day.

The largest known open fault in the United States is basically a giant natural refrigerator.

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

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

This abandoned asylum in Wales might look haunted, but it's still beautiful.

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

The abandoned hospital whose elaborate ghost stories cover up the dirty truth - an uneventful sanitation issue and other mundane reasons for its demise.

Clusters of abandoned buildings hint at the facility's 144-year history with psychiatric health.

The oldest surviving wood-frame building in North America is still in the family.

Unlike other abandoned asylums this empty institution welcomes visitors, just don't go in the buildings.

A well-preserved Ancestral Puebloan ruin tucked beneath a desert cliff.

Memorial of the Salem witchcraft hysteria in the town of Danvers, where it all began.

Manhattan's lighthouse, erected at the insistence of the unsinkable Molly Brown.

Once connected to the outside world by a single train track, this ghost town is looked after by the National Park Service.

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

Located on 420 acres in the high desert, this spiritual center is dedicated to the "science of the future."

The story of Two Guns, Arizona could easily be described as a Shakespearian tragedy on Route 66.

America's oldest archaeological site or a muddled case of wishful thinking.

An abandoned quicksilver mining town surrounded by the Big Bend parks.

An abandoned asylum where patients have been forgotten but their possessions remain.

One of the oldest reform schools in the United States, home to wayward boys such as Merle Haggard, now abandoned.