This Colorado hiking trail provides a small gold mine of abandoned gold mines.

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

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

This bridge is haunted by the ghost of a distraught mother.

Everyone remembers Laurie Strode from Halloween, but this is the house where most of the blood was shed.

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

This fast-food outlet is the only space and UFO-themed McDonalds in the world.

A Swedenborgian glass church surrounded by redwoods sits perched atop a massive landslide area.

A hollow cement depiction of time's inexorable effect on the human body.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

Who needs fancy modern water slides when this giant North Carolina rock works just as well?

148 feet long and in the middle of a verdant forest.

One of the largest-ever mental hospitals now sits abandoned, surrounded by 25,000 unmarked graves.

The eerie remnants of an ancient forest were hidden under the sand for centuries.

A wall of chewing gum moonlights as collective art.

An abandoned village that doubled as "The Hunger Games"' post-apocalyptic wasteland is up for grabs.

An inconspicuous footbridge beloved by San Diego locals.

Visit this playground of waterfalls, caves and sinkholes.

The lush coastal city of Astoria is riddled with forgotten secret sidewalks.

A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

This Florida sinkhole hides a rainforest-like micro-environment in its depths.

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

A ghost town at the airport is now a refuge for blue butterflies.