The ruins of a paper mill destroyed during the Civil War still tower over a tributary of the Chattahoochee River.

One of the first commercially successful anthracite-powered iron-making operations in North America.

A once extravagant mansion, now reduced to ruin.

Locals purchased this abandoned quarry in order to make sure it continues to be overgrown.

The walkable ruins of an 19th century hotel, destroyed in a horse cremation gone wrong.

This Queens hospital has stood abandoned for almost 20 years after its patients were secretly relocated in the dead of night.

Con Edison’s exotic and heat-loving pests.

A human attendant once directed car traffic from this structure before automated stoplights.

The Connecticut village named for its subterranean thunder.

Ruins of a historic medical facility sits eerily by the water.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

A spectacular hidden beach in Ireland has the dark, disturbing nickname of "Murder Hole Beach."

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

Nine of the very few concrete ships ever made in the U.S. are beautifully decaying off a Virginia pier.

This crumbling industrial fortress has attracted daredevils, filmmakers, and historians.

A space-age 1950s pavilion on a secluded path is full of Toronto history surprises.

An abandoned skate park located in the middle of the wilderness.

This enormous World War II relic is one of the largest wooden structures in the world.

Feral cats keeping the rodent population at bay all across Greenpoint waterfront.

A curious friendship between two inanimate ladies.

Just your average Marie Antoinette–themed speakeasy in an abandoned 19th-century subway tunnel.

The factory for the popular Dumbo location, the Greenpoint shop is a quiet gem.

Abandoned power station once home to a squatter community, now being developed into an arts center.

This former lieutenant governor's home is brimming with curiosities.