An ever-evolving wall of graffiti art off East Liberty Street.

The city is full of whimsical portals to another world.

Contrary to what one might expect, ice forms inside this small cavern during the summer and melts during the winter.

The abandoned ruins of America's first private zoo are open for exploration in the Catskills.

A winding, cliffside stretch of road overlooking the Delaware River.

A rock maze opens up to a panoramic viewpoint at an abandoned mine full of ghost stories.

The dairy farm in upstate New York where nearly half a million people gathered for three days of peace and music in 1969.

World's first "penitentiary," meant to be humane, drove men insane.

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

Mysterious rocks that ring musically when struck.

This abandoned amusement park was built on a site with a dark history.

Better known as the "Body Farm," this unique research facility has been studying how human bodies break down since the 1980s.

A stone arch leads to a cavernous 1930s spring house tucked away in the Pennsylvania woods.

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

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

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

Buildings that dynamite couldn't bring down were abandoned because of bathroom issues.

Discovered by cows, these upstate New York show caves are presented with a healthy dose of psychedelic folk art.

This once sprawling resort now sits abandoned, filled with graffiti and vibrant colors from an era long passed.

The graffitied ruins stand hidden within the Pennsylvania woods.

It would take 35 firetrucks to fill this enormous glacial pothole.

Visitors to Salt Springs State Park are encouraged to literally put their two cents in Penny Rock.

World's largest herd of white deer populate a former U.S. Army depot.

An off the grid woodland retreat that harkens back to days long forgotten.