Toxic waste disaster that founded the Superfund program.

A tunnel once abandoned now thrives with graffiti art as an off-limits makeshift gallery.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

The remains of a failed subway in upstate New York is now an underground graffiti bunker.

This once-grand marvel of engineering is now 41 miles of scenic hiking trail.

An abandoned castle owned and ignored by Masons carries a cursed history.

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

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

This disastrous New Jersey safari park saw animal attacks, escapes, and disease before being abandoned.

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

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

Reforestation in action is the main attraction in this abandoned quarry.

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

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

A historic recreation of the golden age of the Erie Canal, abandoned for some time, slowly being restored.

This small road tunnel is the only place where you can cross beneath the Erie Canal.

A 19th century hat factory still stands as a crumbling ruin in upstate New York.

An abandoned tuberculosis hospital moulders on into an uncertain future.

The quarry was abandoned over 100 years ago, after a massive ammunition explosion ended in tragedy.

A ruined mansion hidden in the woods of the Hudson Valley, home of a tragically doomed romance.

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

The remains of what was once the world's steepest passenger funicular.

Reclaimed by nature, the ruins of Doodletown, New York are remnants of a town consumed by a state park.

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