According to local lore, this narrow passageway through two large rocks was accidentally created by the devil himself.

The first declared National Monument in the United States.

Hellam Township is reputed to feature seven remote gates, which when passed through in the right order, open an entrance to hell.

Series of storm drains connected to a dark urban legend.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

This deserted Gold Rush town is home to a Masonic lodge that, strangely enough, still holds meetings.

An occult-y, historic hotel with the World's Largest Ouija board on the roof.

This Cold War missile launch site has been abandoned for 40 years.

The land is home to swimming ponies and a legendary 18th-century treasure.

This golf ball–shaped former desert real estate office now houses a UFO museum.

The artist James Turrell is repurposing an extinct volcano crater as an observatory to experience the cosmos.

A little piece of the Shire is hidden behind a plant nursery in Port Orchard, Washington.

From overly ambitious (and eventually abandoned) atomic dream to bustling office park.

The second tallest railway trestle bridge in America.

One lonely, modern pyramid has gone from corporate think tank to deserted boondoggle.

This imposing 20th-century castle was abandoned before it was ever completed.

The remains of a community that was forced to move for a dam that never materialized still rot in this Pennsylvania park.

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

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

Sited in an Inner Mongolian desert are the remnants of an important trade stop along the Silk Road.

This enormous abandoned prison was once dubbed the "Bastille of Romania."

The ruins of a Massachusetts prison farm can still be found crumbling the woods of a state park.

An abandoned tuberculosis hospital said to be haunted by the patients who died within its walls.

Unlike other abandoned asylums this empty institution welcomes visitors, just don't go in the buildings.