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

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

Hundreds of numbered stakes hidden in the woods mark the graves of the lost souls of a nearby asylum.

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

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

The remains of the furnace and iron works that produced the massive Hudson River Chain still stand in the woods of New York.

Fears of Satanic worshippers swirl around five Celtic-inspired megaliths.

This elaborate High Victorian Gothic structure is one of the world's few 16-sided buildings.

This stained glass window designed by Tiffany Studios is hidden behind the circulation desk of a public library.

A man used his Civil War-era fortune to build this sanctuary in memory of his wife.

A CT scan revealed the identity of this 3,000-year-old mummy that everyone erroneously thought was female.

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

The oldest church in Iceland is one of the few to feature ornate decoration.

This abandoned cemetery is crumbling into ruin, exposing the artifacts and bodies buried there.

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

Two islands just 4 km apart separated by an International Border and Date Line.

This ghostly Alaska village still clings to a steep cliffside despite having been abandoned for over 50 years.

The oldest county library in the United States.

A historical puzzle lies at the origins of this structure.

The ruins of a medieval castle that once belonged to one of the most powerful families in the Netherlands.

The first crematorium in the Netherlands.

A miniature village lies nearly forgotten in the forest by the side of a major highway.

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

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