Ancient petroglyphs discovered only after a massive fire swept across Michigan in the 1880s.

The largest earthwork effigy in the world.

Mysterious ancient boulder carved with petroglyphs in the mountains of Western North Carolina.

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

This empty Victorian manse on Staten Island is said to be haunted but is actually a real life crime scene.

Peek through the gates at this oasis from the city, full of Old English charm.

Unique antiquarian shop specializing in globes, maps, and prints.

The famous author's cottage hideaway.

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

Despite finally receiving electricity in 1970, this tiny town is now deserted.

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

A historic covered bridge, only one of two remaining in North Carolina.

Ruins of an American Civil War iron forge still survive today.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

A formerly abandoned mental institute, now back in business.

This hospital once pioneered the use of electroencephalograms, but fell into maltreatment, abuse, and eventual abandonment.

The haunting, dilapidated remains of a former poorhouse on Staten Island's Greenbelt.

The inspiration for H.P. Lovecraft's horror stories and Batman's Arkham Asylum is now a condominium complex.

The longest navigable underground river in the United States is home to countless blind and albino animals.

A ship that lived many lives under many names is now known merely as the "Ghost Ship."

One tree's homage to soles past and present.

A hidden network of subterranean passageways lies tangled beneath Indianapolis' bustling City Market.

The largest historic preservation organization in the United States.

Ruined pieces of stone and a swimming pool are all that remain of an amusement park swept away by a flood.